Public sector workers in the Department of Work and Pensions overwhelmingly threw out the government�s below-inflation pay offer yesterday.

Public sector workers in the Department of Work and Pensions overwhelmingly threw out the government's below-inflation pay offer yesterday only hours after Gordon Brown warned trade unions he would make no concession on the staging of public sector pay.

Members of the Public and Commercial Services Union, 76% of whom rejected the three-year pay deal which sees increases for longer-serving staff members of 2% this year, 0% next year and 1% in the final year, will now ballot all of its members at the end of the month on the possibility of a nationwide strike.

Mr Brown, making his first prime ministerial speech to the TUC Congress, brooked no quarter although he was confronted by 60 delegates holding placards saying "Fair Pay for Public Servants".

Instead, to the dismay of the delegates, some of whom had been hoping for a more conciliatory approach from Mr Brown after their difficult relationship with Tony Blair, he was adamant economic stability was a greater priority than public sector pay.

While he acknowledged the positive aspects of the trade unions and spoke in respectful rather than hectoring tones, he said: "If we were to again allow inflation to get out of control by repeating the same mistakes of 15 years ago we would be back to the same familiar pattern of spiralling prices, high unemployment, a mortgage crisis and public spending cuts.

"And it is because we must never return to those days, when reckless promises that you could simultaneously cut taxes, raise spending and cut borrowing were made and then inflation was allowed to get out of control causing three million unemployed, £16bn public spending cuts, and a wave of half a million repossessions, that this government will always put stability first," he added.

Mr Brown's arrival at Brighton had been anticipated with high hopes but both the delegates' welcome and their reaction to his speech were subdued. Contrary to what he might have expected, he did not receive a standing ovation when he walked on to the stage or when he walked off.

Later, when the result of the PCS ballot was known, Mark Serwotka, the general secretary of the union, said: "The rejection of this pay offer sends a clear signal that the people who have delivered the lowest unemployment in a generation, pension credits and the New Deal aren't prepared to accept pay cuts in real terms.

"With a quarter of the civil service earning less than £16,000, the government needs to wake up and recognise that hardworking civil servants and the public won't stand for being used as an anti-inflationary tool."

Colin Moses, chairman of the Prison Officers' Association, which is involved in a pay dispute with the government, said: "I wish the Prime Minister would listen rather than lecture. I never thought I would hear such a speech from a Labour Prime Minister."

Although the Prime Minister's speech struck an inflexible tone on pay, Mr Brown did say he would continue to support proposals to give agency workers protection throughout the EU, and he focused on the need for training and skills.

Tony Woodley, joint general secretary of Unite, acknowledged the PM only a "lukewarm" reception.

He said: "It was more of a lecture than a speech. Parts of it were very welcome, such as stronger enforcement of the minimum wage and more jobs. But I would have liked him to criticise fat cats in the City and to say that he will support new laws for agency and temporary workers."