Civil and public servants overwhelmingly rejected the Government's pensions offer today, setting the stage for a fresh round of industrial action.
The Public and Commercial Services Union (PCS) said its consultation ballot of members had shown support for continuing a campaign against pension changes.
Some 90.5% of those who took part in the ballot rejected the Government's proposals for a new pension scheme, and 72.1% backed continuing the campaign, including further industrial action with other unions.
The national executive committee of the PCS, which represents around 290,000 civil and public servants, will now meet on Monday to consider the ballot results, the position of other unions and to decide on the next step.
PCS general secretary Mark Serwotka said: "Civil and public servants can see that this Government simply wants to make them pay for the mistakes of bankers and politicians, and have rejected by a massive margin this attack on their pensions.
"Ministers must now seriously engage in negotiations on the core issues if they want a settlement.
"The vote shows we remain committed to resisting this Government's attacks on pensions, jobs and pay, and to working with other unions to build further co-ordinated industrial action."
The Government has been embroiled in an ongoing row with unions over the future of public sector pensions.
While some have now agreed to accept a deal, other unions have rejected the Government's offer, maintaining that it will leave then working longer, paying in more and receiving less when they retire.
Ministers argue that changes are needed to make pensions sustainable for the future.
Announcing the one-day London strike today, NUT general secretary Christine Blower said: "The Government is well aware that teachers do not accept the changes that they propose to make to our pensions. The vast majority of teaching unions have not signed up to the latest pension proposals which still mean that teachers will have to pay much more, work much longer and get much less in retirement.
"The NUT believes it is essential that the teaching profession stands united on this issue. Working and taking action together in June and November 2011 brought some concessions from Government, but they do not go far enough. We have no evidence whatsoever that teachers' pensions are unaffordable."
London-based members of the University and College Union (UCU) who are part of the Teachers' Pension Scheme will also take part in the walkout on March 28.
And the Rail, Maritime and Transport union said yesterday that more than 600 of its members at the Royal Fleet Auxiliary, which supports and services the Navy, will walk out on March 28.