Police budgets in England and Wales will be protected in real terms, Chancellor George Osborne has said in his Spending Review.
There had been fears the police budget in England and Wales would face significant cuts.
But Mr Osborne said: “Now is not the time for further police cuts, now is the time to back our police and give them the tools to do the job.”
He also said the counter-terrorism budget would be increased by 30%.
'Protect the police'
Policing is not a protected area of public spending and it had been thought Mr Osborne was considering cuts in police budgets of up to 20% as he sought to make savings of £20bn.
Mr Osborne told the Commons that he had “received representations” from shadow home secretary Andy Burnham that police budgets should be cut by 10%.
But Mr Osborne said: “I am today announcing that there will be no cuts in the police budget at all, there will be real terms protection for police funding.
“Mr Speaker, the police protect us and we are going to protect the police.”
The BBC's home affairs correspondent Danny Shaw said police at a joint conference of National Police Chiefs' Council and Association of Police and Crime Commissioners in Manchester had looked “astounded” at the news.
He tweeted: “Got to say: I didn't see that coming. And no one at the police conference did either. Was it Paris that changed the Govt's mind? #CSR”
Kevin Hurley, police and crime commissioner for Surrey, said the response to the news was “almost like euphoria if your football team had scored a goal”.
“The police and crime commissioners and chief constables are delighted, but of course we should remember we are already in the process of implementing cuts, so all is not well in the world.
“We will see further reductions in policing on the earlier planned cuts but this is really good news. Fair play to the chancellor, he has listened.”
Mr Osborne said police reform needed to continue in this Parliament and that investment was needed in new mobile communications for emergency services and new technology at “our borders”.
He said police forces would be able to make further savings by merging back offices and “sharing expertise” and said the government would be offering a new fund to “help this reform”.
Mr Osborne also said police and and crime commissioners would have “greater flexibility” to raise precepts – the money given to police through council tax – where they had been “historically low”.
The Treasury said police spending would be protected in line with inflation, which would represent an increase of £900m by 2019-20.
Prior to the Spending Review, police forces have faced significant cuts since 2010.
According to the Institute for Fiscal Studies spending on police services in England and Wales fell by 14% in real terms between 2010-11 and 2014-15.