Alex Salmond has admitted his government will not fulfil its election promise to recruit 1000 extra police officers, prompting accusations that he had betrayed the people of Scotland.

The First Minister and Justice Secretary Kenny MacAskill have been under intense pressure from opponents and leaders of rank-and-file officers to honour a manifesto commitment to raise the policing complement by 1000, a pledge Mr Salmond also made to the Scottish Police Federation conference when he cited a £78m fund.

Earlier this month, The Herald revealed ministers had asked a senior civil servant to find efficiency savings to help them meet their promise, which led to a rebuttal from the administration.

Yesterday, however, during rowdy exchanges at the Scottish Parliament, the First Minister said his government would instead boost numbers through recruiting some new officers, but also by persuading some not to take early retirement and by freeing up others from desk duties.

That led to opposition claims that the First Minister was "wriggling, squirming, and writhing" to disguise the fact he is about to break one of the SNP's key manifesto pledges.

During First Minister's Questions, Mr Salmond was pressed on this by both Annabel Goldie, the Conservative leader, and Wendy Alexander, the Labour leader, who also accused the SNP of breaking election promises to reduce class sizes and give grants to first-time house-buyers.

Ms Goldie said: "Will he now come clean, admit that the SNP cannot be trusted and that he has betrayed the public and he has betrayed our police?"

Ms Alexander told Mr Salmond: "You are boasting to your conference delegates this weekend about a can-do attitude in Scotland because the SNP are in government. The real truth is what the SNP can do is to make promises - what they can't do is to keep them."

Mr Salmond refused to give details of the government's plans ahead of the budget speech, which is due to be delivered on November 14, but insisted police numbers would go up.

He said: "We will deliver an additional 1000 police officers in our communities through increased recruitment, improved retention, and redeployment."

Later, further pressure was placed on the government when a Conservative motion calling on ministers to ensure police numbers increase from 16,234 to 17,234 by 2011 was passed by 77 votes to 48, thanks to the support of Labour and the Liberal Democrats.

Bill Aitken, the Conservatives' justice spokesman, said it was now up to the government to make sure it met its election promise. He said: "Let us be quite clear - what was promised was 1000 additional officers. No ifs, no buts, no maybes - and not their full-time equivalent."

Mr Aitken added: "This Parliament needs answers and the people of Scotland demand them. This is a pivotal moment for the SNP government. It is time for them to put up, put their money where their mouth was, and keep this clear manifesto promise."

Meanwhile, the government yesterday announced it was reviewing legislation introduced three years ago to improve community safety.

Fergus Ewing, community safety minister, said the Antisocial Behaviour Act had made "a real difference" in some areas, but further research was needed into its overall effectiveness.