The warning followed a decision by the Public and Commercial Services Union (PCS) yesterday to ballot 280,000 civil servants for industrial action in protest at the low inflation pay deals.

General secretary Mark Serwotka bitterly attacked the Prime Minister, saying Gordon Brown should "hang his head in shame" at the way civil servants were being treated.

He told his union's annual conference in Brighton that Labour came to power in 1997 under the slogan "things can only get better", but, for civil servants hit by job losses and pay cuts, things had got worse.

"The treatment we have received at the hands of this Government is an absolute disgrace – more privatisation than under Margaret Thatcher and John Major combined."

Mr Serwotka continued: "We are faced with a Government and a Prime Minister who has said he wants to reduce the size of the Civil Service to its 1945 level – a time of rationing and hardship when the country only had a minimal welfare state.

"What a miserable statement from a miserable Prime Minister who, in his desperation to avoid the humiliation of defeat at the hands of a bunch of lacklustre Tories, apes their policies in a pathetic attempt to sound tough."

The 1,000 delegates agreed to ballot civil servants across 200 Government departments and other agencies for a programme of rolling industrial action, including a national one-day strike as well as bans on overtime and other working-to-rule.

Delegates also pressed for ind-ustrial action to be coordinated with other public-sector unions after last month's walkout by hundreds of thousands of teachers, lecturers and civil servants – the biggest stoppage over pay in the public sector for a decade.

Mr Serwotka said after the vote: "At a time when the Labour Government is at its least popular they are further alienating their own workforce with a policy of pay freezes and pay cuts.

"Pay in the Civil Service is amongst the lowest in the public sector, with a quarter earning less than £16,000 and thousands on the minimum wage.

"It is a disgrace that you have essential workers, such as coastguards, being paid just above the minimum wage and 40 per cent of job centre staff receiving no pay rise at all this year."

Mr Serwotka told a news conference later that the union was planning a "faster pace" of industrial action which would include targeting specific Government departments such as the Prison Service, Home Office and Crown Prosecution Service to cause maximum impact.

He said industrial relations had "completely broken down" and accused Mr Brown of "playing politics" with people's lives. Civil servants, "demoralised and dep-ressed", were leaving the service.

Later it was announced that college lecturers in London will strike on June 9 unless a 2.5 per cent pay offer is improved.

The University and College Union also warned that lecturers throughout England could intensify industrial action at the start of the autumn term.

The union's annual conference in Manchester next week will consider calls for joint campaigns with other public-sector unions over pay.

Lecturers are seeking a six per cent rise to compensate for a below inflation settlement last year and to bridge a pay gap with teachers. Lunchtime protests will be held throughout England on June 4 ahead of pay talks the following day.

The National Union of Teachers executive will meet today to consider its next move following last month's strike over pay.

Acting general secretary Christine Blower told the PCS conference: "The campaign will certainly go on until we have fair pay for teachers and all public sector workers."

NUT president Bill Greenshields warned that the pay dispute would lead to a shortage of teachers and increased class sizes unless it was quickly resolved.

Meanwhile the Fire Brigades Union warned of possible industrial action this summer, saying their pay formula, agreed after their bitter strike of 2002-3 was "cracking at the edges".