The Government's Funding for Lending scheme, introduced in August 2012, has been blamed for making savers' plight worse as it gave banks access to cheap funding to help mortgage borrowers, making them less reliant on having to attract savers' deposits.
The scheme has been redirected away from households for 2014.The consumer group also found that in February 2008, the average instant-access savings account paid a rate of 4.14%, but that has now plummeted to 0.63%
. This six year slide would equate to an annual loss of £351 for someone saving £10,000 in an average instant-access savings account.
Instant access and cash Isa accounts have suffered around 20 rate cuts a month on average over the last year and a half, consumer group Which? has found.
The research found savings providers have hacked rates on these accounts 343 times since August 2012, despite the Bank of England base rate being stable during that time at 0.5%
Which? found that rates have even been slashed at the height of "Isa season" - the period around the end of the tax year when providers would normally be expected to ramp up competition to attract people who are looking for somewhere to put their Isa allowance or that for the next tax year.
The Financial Conduct Authority chief executive has said a study of introductory rates for savings in banks will enable the FCA to better understand the dynamics that drive the market and the decisions that consumers make.
Martin Wheatley said: "We know that switching rates are low for financial services products and savings accounts are no exception.
"Even when people do switch their accounts, they are twice as likely to go with their existing provider than move to the offering of a competitor."
The use of introductory rates to tempt savers is to be reviewed by the financial regulator as part of a wider study into the £1 trillion cash savings market.
The Financial Conduct Authority wants to assess whether competition is working in the best interests of consumers, particularly in terms of them getting the best returns possible and information to meets their needs
As well as teaser rates, where introductory deals are offered to new customers, the FCA will want to know how often consumers switch their savings accounts.
Britons are saving more than ever before, according to new findings.
Treasury-backed savings body NS&I found that savers are putting 8% or £104 of their income aside each month - the first time the sum has broken the £100 barrier.
People aged 25 to 34 are putting aside just over 9% of their incomes each month - or £125 - the highest average figure recorded for this group since 2010.
John Prout, NS&I retail customer director, said: "The research suggests that most age groups in Britain are saving more and this corresponds with an increased use of savings goals from last summer, which can only be an encouraging sign for the future."
Greater flexibility may be needed in pension saving, the head of investment propositions at Scottish Widows has said in response to a new study that shows that the next generation may have to start saving at 25 years old to retire by their 70s. Iain McGowan said:
Someone born in 2012 could expect to build up £73,000 worth of student debt, according to economist Steve Lucas.
According to a new study, financial pressures from university and housing costs will mean the next generation would have to start saving at the age of 25 to prepare for 30 years of retirement. Mr Lucas said:
The next generation face being in their 50s before they have paid off their student loans and in their 60s before they are mortgage free, research has shown today.
The Scottish Widows study argued that rising life expectancies, combined with people being saddled with large debts earlier in life, mean that today's children should start saving for their retirement at the age of 25 if they want to enjoy a comfortable old age.
Economist Steve Lucas argued that financial pressures from university and housing costs will mean that the next generation will only be able to afford smaller pension contributions, meaning they need to start saving from around 25 years old to prepare for 30 years of retirement.
A fifth of households said they have no emergency cash while another 12 per cent said they have less than £250 for a rainy day.
It is generally recommended to build up a minimum of three months take-home pay as a "salary cushion", typically £5,756.
Some 28 per cent of those who took part in the survey said they would be unable to cover rent or mortgage payments if they unexpectedly lost their income.
One in 10 said they would be forced to rely on a credit card, personal loan or an overdraft.