LONDON (Reuters) - British civil servants will vote next month on nationwide strike action to put pressure on the government to abandon its 1 percent cap on public sector pay rises, their main trade union said on Wednesday. Prime Minister Theresa May s government is considering lifting the cap for at least some public-sector workers later this year, according to media reports earlier this week, as disquiet grows over pay restraint that has lasted since 2010. But on Wednesday May would not commit to lift the cap for nurses - who are widely thought likely to get an increase - after opposition Labour Party leader Jeremy Corbyn challenged her in parliament over wages in the public and private sector. The Public and Commercial Services union (PCS), the main union for civil servants, said it would ballot nearly 200,000 members between Oct. 9 and Nov. 6 to assess appetite for what would be their first nationwide strike since October 2014. If there are no concessions on pay after the first ballot, the union will hold a second ballot to confirm support for specific strike action.  Pay misery for public servants must end and the government must restore public-sector pay to levels that allow working people to live with the dignity and security they deserve,  Mark Serwotka, the PCS s general secretary, said in a statement. The PCS said it wanted pay rises of at least 5 percent for all public-sector workers. Average weekly earnings in the public sector rose by 1.3 percent over the past year, compared with a 2.2 percent rise in private-sector wages. Consumer price inflation was 2.6 percent over the same period. Some 5.4 million Britons work in the public sector, of whom just over 400,000 work in the civil service. Most public-sector staff work as teachers or in the National Health Service. 