Video report by ITV News Political Correspondent Shehab Khan
New restrictions and toughened fines for failing to self-isolate come into force across parts of the UK on Monday.
People across England now face a fine of up to £10,000 for breaking, the now legally required instruction, to self-isolate if they test positive for coronavirus or are contacted by the test and trace service.
New fines for law breakers start at £1,000 and increase up to £10,000 for repeat offenders or serious breaches.
Those who test positive for Covid-19 will also be fined if they knowingly provide false information about close contacts to the test and trace service.
The Department of Health and Social Care (DHSC) warned from Monday, police will check compliance in the highest incidence areas and in high-risk groups based on “local intelligence”.
Labour believe people are confused, however, by the changing advice and public health information available - leaving many vulnerable to fines.
Some fear people will avoid getting tested to find out if they have coronavirus - or get a false positive result - to ensure they do not have to self-isolate and risk the monetary penalty.
"I think if people are willfully and deliberately ignoring the rules, of course we will want to see firm action and for those people to be prosecuted," Shadow Education Secretary Kate Green told ITV News. "I wouldn't, however, want to see people deterred from going for a test, from saying that they are going to need to self-isolate because they fear if they make a mistake, if they are going to make a swingeing fine or, for that matter, lose wages, and we know the support the government is putting in, the financial support for people who have to take time off work to self-isolate isn't really sufficient.
Labour MP Kate Green speaks to ITV News:
"It is important people follow the rules, yes it's important people that people don't deliberately ignore those rules - there are consequences - but there is an important balance.
"I think people are genuinely confused about the rules because of the constant changes in them and guidance and what happens in different parts of the country.
"We have to say the government needs to make things much clearer for people because that will help us all follow the rules that we should."
Health Minister Helen Whately
Health Minister Helen Whately says the fines are a "last resort" when it comes to punishing any potential rule breakers.
"The first thing is that people recognise we have a responsibility here, as a whole community, as a whole society, we have Covid under control because each one of us can get it and spread it onto somebody else," Ms Whately told ITV News.
High profile and "egregious" cases of non-compliance will be investigated and prosecuted, while action will be taken on tip-offs from "third parties" about people who have tested positive but are not self-isolating, the DHSC added.
Under new rules in England mean wedding ceremonies will also be restricted to 15 people from Monday.
Ms Whately has said the government could not rule out further restrictions if coronavirus infections continued to rise.
“We don’t want to bring in more restrictions but of course we keep a constant eye on what’s going with the Covid rates and we have seen these upward trends in recent weeks,” she told Sky News.
“This is the moment in time we have an opportunity, we have a choice as a country to get this back down under control.
“We have to break these chains of transmission. That’s the way we get the rates back down again. We have seen them going up again in the last two weeks.”
Meanwhile, three more council areas in South Wales will go into local lockdown from 6pm on Monday, the Welsh Government has announced.
Neath Port Talbot, Torfaen and the Vale of Glamorgan will be covered by the restrictions, which mean people will not be able to enter or leave the areas without a reasonable excuse.
They will not be able to meet indoors with anyone they do not live with, with extended households suspended.
Restrictions are already in place in Cardiff, Swansea, Llanelli, Blaenau Gwent, Bridgend, Caerphilly, Merthyr Tydfil, Newport, and Rhondda Cynon Taf.
It means more than half of the population of Wales is now in some form of localised lockdown, with the majority of the south of the country under tougher restrictions.
It comes after bans on households mixing came into force in parts of England too.
Restrictions in Wigan, Stockport, Blackpool and Leeds were all tightened on Saturday, while stricter rules are already in force across large swathes of north-west England, West Yorkshire, the North East and the Midlands, as well as parts of west Scotland.
The new restrictions in three areas of Wales means an estimated 17.8 million people across the UK will be living under additional coronavirus measures by Monday evening - on top of those announced by Prime Minister Boris Johnson.
It comes as the day-on-day rise in confirmed Covid-19 cases in the UK hit 5,693. While a further 17 people had died within 28 days of testing positive for coronavirus as of Sunday.
Health Secretary Matt Hancock said the government will “not hesitate” to introduce further measures if case numbers continue to rise.
He added: “Anyone can catch coronavirus and anyone can spread it.
“We all have a crucial part to play in keeping the number of new infections down and protecting our loved ones.
“As cases rise it is imperative we take action, and we are introducing a legal duty to self-isolate when told to do so, with fines for breaches and a new £500 support payment for those on lower incomes who can’t work from home while they are self-isolating.
“These simple steps can make a huge difference to reduce the spread of the virus, but we will not hesitate to put in place further measures if cases continue to rise.”
Prime Minister Boris Johnson faces a Commons defeat on Wednesday as Tory rebels continue to press the government to give MPs a chance to vote on coronavirus measures before they come into force.
Conservative former chief whip Mark Harper became the latest backbencher to say he would back the amendment unless ministers back down.
The government has also pledged an “uninterrupted” supply of personal protective equipment has been promised by the Government for health and social care workers in England as coronavirus cases rise.
The DHSC said four-month stockpiles of items like face masks, visors and gowns will be in place from November.
The DHSC said that six million people had downloaded the NHS Test and Trace App the first day it launched, and this had since risen to 10 million by midday on Sunday.
Ministers are also under growing pressure to review the “hard” 10pm curfew on pubs, bars and restaurants amid criticism that the new rules are leading to revellers filling streets en masse.
Crowds of people were pictured on Saturday night gathering in city centres and piling onto public transport, while long queues formed at off licences after venues kicked customers out at 10pm.
But Culture Secretary Oliver Dowden insisted on Sunday that there was “definitely science” behind the curfew, despite a scientist advising the government saying he had “never heard” the measure discussed at Sage meetings.
Mr Dowden also said that university students should be able to return home to their families at Christmas if the country “pulls together” and observes the new coronavirus rules.
The Government is under pressure to guarantee young people are not confined to their halls of residence over the festive period because of Covid-19 outbreaks on campuses.
Thousands of students are currently self-isolating in their rooms following a surge in cases at institutions including Glasgow, Manchester Metropolitan and Edinburgh Napier.
Students in Scotland have been told they can return home from university accommodation on a long-term basis, as long as they follow rules on self-isolating.
Meanwhile a growing number of current and former MPs have called for students who have had their education disrupted by the pandemic to be offered refunds.
Former transport minister George Freeman on Sunday joined Conservative chairman of the Education Select Committee Robert Halfon and former Labour education minister Lord Adonis in pushing for compensation for students who have been forced into lockdown.
Mr Freeman told the BBC universities should “look seriously” at offering students “reduced fees if they’re not getting the full experience”.
The calls come after Glasgow University said on Saturday it would refund all students in halls of residence one month’s rent, along with a £50 payment for food, after an outbreak of cases.