It is always wise to remember that what you say in front of a police officer may be used in evidence against you. In front of the massed ranks of the Scottish Police Federation at their conference in April, Alex Salmond gave in to pre-election temptation and delivered a guaranteed vote-winner. He undertook that if the SNP formed the next administration at Holyrood, Scotland would have an extra 1000 police officers. The delegates had heard it all before, so they questioned him more closely. In particular, Les Gray, chairman of the Strathclyde joint branch board, elicited from Mr Salmond that £78m was being set aside to pay for the officers. His audience believed that if the SNP were to win the election, the number of police officers in Scotland would increase from approximately 16,200 in 2007 to approximately 17,200 in 2011. Yesterday that was used in evidence against Mr Salmond as First Minister. Annabel Goldie, leading the prosecution for the Conservatives, drew out the imprecise answer that an additional 1000 police officers would be delivered "through increased recruitment, improved retention and redeployment".

It is always wise to remember that what you say in front of a police officer may be used in evidence against you. In front of the massed ranks of the Scottish Police Federation at their conference in April, Alex Salmond gave in to pre-election temptation and delivered a guaranteed vote-winner. He undertook that if the SNP formed the next administration at Holyrood, Scotland would have an extra 1000 police officers. The delegates had heard it all before, so they questioned him more closely. In particular, Les Gray, chairman of the Strathclyde joint branch board, elicited from Mr Salmond that £78m was being set aside to pay for the officers. His audience believed that if the SNP were to win the election, the number of police officers in Scotland would increase from approximately 16,200 in 2007 to approximately 17,200 in 2011. Yesterday that was used in evidence against Mr Salmond as First Minister. Annabel Goldie, leading the prosecution for the Conservatives, drew out the imprecise answer that an additional 1000 police officers would be delivered "through increased recruitment, improved retention and redeployment".

Further detail about exactly how many additional police officers will be recruited must wait until the SNP delivers its budget on November 14. It is now clear that retention and redeployment will form a key part of ensuring there are more officers engaged in front-line policing. Numbers apart, there should be no quarrel with that general strategy. Mr Salmond is right to say that police officers who build strong relationships with their local areas deter crime, solve crime and make people feel safer. There are some desk jobs that can be done as effectively by civilians as by expensively trained police officers and, where appropriate, they should be redeployed to provide a visible presence on the streets and provide a faster response to incidents. The more difficult issue is the retention of long-serving officers, 2000 of whom will have the option of retiring over the next five years as a result of a peak in recruitment in the 1970s. Kenny MacAskill, the Justice Minister, concedes that we should retain experienced officers who cannot easily be replaced because they have acquired "skills that cannot be learned in college". Yet they can only be retained if policing remains a more attractive option than alternative offers from the private sector; increasing numbers is one way to improve morale.

There is no means of knowing how many police officers, or anyone else, cast their votes in favour of the SNP as a result of Mr Salmond's promise on recruits. It was not just made verbally at the SPF conference, but spelled out in the manifesto: "We will set out plans in our first Budget for Scotland for 1000 more police We want to see these new police officers becoming part of the fabric of communities." The clear import of the words more and new is that these officers would be additional. However they voted, police officers and public alike will feel cheated if the SNP's budget fails to honour the manifesto.