The PM's spokesman says today's strikes were "unnecessary" and that the "impact has been limited". He said borders managed without delays.
Have today's public sector strikes had the desired impact or did they simply fall short?
Prison officers across England, Scotland and Wales have returned to work after their walkout over changes to their retirement age.
250,000 civil servants are to be balloted on strikes over pay, pensions and working conditions, said the PCS union.
GMB suspended threatened strike action earlier this year over the introduction of new rosters which the union said would have led to a reduction in incomes of members after the company agreed to enter talks. Talks broke down last Friday.
GMB organiser Gary Pearce said: "GMB negotiators have been in talks to reach an agreement to resolve this issue since the agreed suspension of the strike action scheduled over Easter.
"It is a shame that Swissport has made and then withdrawn a number of proposals including a return to the original four-days-on and two-days-off roster which would have settled the dispute. The proposals were withdrawn last Friday."
Stansted airport is set to be hit by seven days of strike action by ground staff belonging to the GMB union.
The action, by staff employed by ground service company Swissport, includes stoppages over the Queen's Diamond Jubilee bank holiday weekend at the beginning of June.
- The first of the stoppages, in a dispute over rosters, will be from 5.30am on Wednesday to 5.30am on Thursday.
- There will also be strikes from 5.30am on Saturday until 5.30am on Monday May 28 and from 5.30am on Saturday June 2 until 5.30am on Wednesday June 6.
- The June 2-6 strike includes the two Jubilee bank holiday days of Monday June 4 and Tuesday June 5.
– General Secretary of Unite Len McCluskey
Today has been a fantastic success and there will be more strikes in June, at the end of the summer, the winter, next spring and on and on and on.
We need to make it clear that the coalition of resistence we have with groups such as students and senior citizens is generating momentum.
The PM's spokesman said: "Clearly, we think the industrial action is unnecessary. We have set out our proposals for reforming public sector pensions.
"We think they are fair, we think they ensure that public sector pensions remain among the very best available and they mean we can sustain that system into the future.
"I think most people recognise that the Government has to deal with the financial situation it is faced with and that that means taking some difficult decisions to cut public spending."
Prime Minister David Cameron's official spokesman said Downing Street believed the impact of today's strikes to have been limited, thanks in part to "robust" contingency plans.
"My information is that the impact of the strike has been quite limited."
"The situation on the borders has been managed well and without delays and the vast majority of Job Centres have remained open, so the contingency plans have been working."
Contingency plans have involved drafting in additional people to man border posts, including some who have been trained up to work in the busy periods expected during the Olympics.
Minister for the Cabinet Office, Francis Maude, said: “The dedicated majority of public sector workers are working normally today and rigorous contingency plans are ensuring that nearly all key public services remain open as usual.
“We can now confirm that:
- Just 102,244 civil servants are on strike – down from 146,000 in November and dramatically lower than union claims;
- Our borders have been managed without delays and staff in northern France have prevented 25 people attempting to evade our border controls;
- This morning's industrial action by prison officers is now over, staff are returning to work and our contingency measures were effective."
Andy Springthorpe, a sergeant with West Midlands Police, said: "It's not just about our pensions, it's about the changes the Government wants to impose that will fundamentally change the way we police our communities.
"Why repair something that isn't broken? It's very frustrating."
Sgt Springthorpe, who has been a policeman for more than 22 years, said his force was subject to Regulation A19, meaning that officers with more than 30 years of service are forced to retire.
Inspector Eddie Boyle, who has 28 years' service and currently works for West Midlands Police, said: "We appreciate the situation the Government is in financially and we want to play our part in addressing it. But we almost feel like it's a personal attack on the police service."
To read more about West Midlands Police officers who took part in the march visit ITV Central.