Police officers were drafted in to cover for striking control room staff today as Labour launched a campaign calling on the "reckless" Government to drop plans to reduce force budgets by 20% over four years.
Unison said hundreds of police support officers (PCSOs), call handlers, administrators and custody officers in Nottinghamshire took industrial action over job cuts and restructuring, with a further 24-hour stoppage planned for Friday.
It was the first strike by civilian police staff in the current wave of union protests against public sector spending cuts, which has led to industrial action by thousands of council workers across the country.
Nottinghamshire Police said the strike was not having a major impact after contingency plans were drawn up, including officers standing in for control room staff.
The union is in dispute over restructuring amid plans by the force to save more than £40 million in the next four years to "reshape" the county's police and "transform" the services it provides.
Assistant Chief Constable Ian Ackerley said 999 and other non emergency calls were being answered quickly, adding: "We had asked Unison to allow our control room staff to be exempt from industrial action due to the critical nature of the work they do. They would not agree to that. Consequently we have put police officers into that role."
Unison said police forces up and down the country were making "massive" cutbacks, as a result of 20% budget cuts meted out by the Government, warning this will lead to the loss of 16,000 police staff and 1,800 police officers.
"There is no doubt that cuts on this scale will see our streets become less safe. We are calling on the Government to think again," said Unison leader Dave Prentis.
"Police staff are dedicated public service workers - they do not want to go on strike, but they have been left with little choice.
"More than 100 police staff have already lost their jobs, and another 746 are at risk of redundancy. Police staff do vital jobs in our communities and in every police force - taking 999 calls, doing forensic investigations and liaising with victims of crime.
"These cuts are not being made on a fair or equal basis. We are urging the force to get into talks through arbitration and avoid any further action."
Labour leader Ed Miliband urged ministers to learn from the recent riots when he visited Lewisham, one of the London boroughs hit by this month's disturbances.
"We are launching a campaign to force this reckless Government to think again on police cuts that can only weaken the forces of law of order on our streets when there is such widespread concern over the safety of our communities," said Mr Miliband, who is pledging to force a vote in the House of Commons on the funding cuts.
"If there is one lesson we should all learn from the riots, it is that it was crucial to have our police bravely standing between home and shops on the one hand - and lawlessness on the other.
"They are speaking hollow words when this Government insists on spending £100 million to create a new tier of politicians through elected police chiefs at the same time as cutting the number of officers on the street.
"And they are speaking hollow words when David Cameron pledges the Treasury will stand behind policing costs during the riots but has done no such thing, leaving forces across the country with the prospect of making even deeper cuts than they are currently planning."
Asked about today's strike, he said: "I don't think that strike action is the solution.
"The solution is for the Government to hear the message that I'm putting forward, that others are putting forward, which is that they shouldn't be going ahead with this scale of cuts, 16,000 fewer officers, and I'm determined to force a vote in Parliament on this issue."
Policing minister Nick Herbert said: "It is simply hypocrisy for Labour to campaign on this when they proposed to cut £1 billion a year from the police budget. We have to deal with the deficit which Ed Miliband helped to create, and as a service spending over £14 billion a year the police can and must play their part.
"With 25,000 officers in backroom jobs, forces can make savings and still protect the frontline."
Earlier this year, Home Secretary Theresa May insisted the average reductions for forces' grant in cash terms would be 4% in the first year, 5% in the second, 2% in the third and 1% in the fourth.
She said pay freezes and a reduction in red tape would mean the impact of the reforms would be "less severe" than people feared.