Ken Livingstone was today accused of breaking a key re-election pledge to put 1,000 extra police on the streets of London.
The Home Office has turned down his bid for some of the extra officers meaning London will get only 800 more.
This will include an extra 97 royal and diplomatic protection officers which the Mayor had originally suggested would be out on the beat.
Mr Livingstone admitted that his original promise had been a "bit over the top".
Tory mayoral candidate Boris Johnson said: "Of the 1,000 extra officers that Mayor Livingstone said were to be policing the streets, it turns out that 300 were for royal and diplomatic protection. And now the Home Office are only providing funding for a fraction of them.
"Not only was his original pledge of 1,000 extra officers a sham but his own Government has now taken away funding for him to meet it. He is... resorting to making inflated promises to try to win this election." Liberal Democrat Assembly member Graham Tope added: "The Mayor should not make budget pledges unless he knows he has the power to enact them.
"It is clear that he does not have the support of the Home Office to provide these extra police and you have to ask why the Mayor did not ensure their backing before now."
At the time of his promise, the Mayor's office cautioned the exact increase would depend on the outcome of the Met's bid for extra funding for counter terrorism, security and Olympics planning.
There are currently 30,996 police officers, 4,012 community support officers and 14,061 civilian staff in the Met.
Mr Livingstone said today: "Even with the reduction in the designated security posts we expect to provide 1,000 extra police in London next year. This will be on top of an extra 10,000 uniformed police officers in London, an increase in uniformed officers of 39 per cent compared to 2001."
