The chief constable of West Yorkshire Police has said he was "disappointed" to see his officers used as a "backdrop" to a political speech by Boris Johnson on Brexit and Jeremy Corbyn.
John Robins said on Friday that the force had agreed for its officers to be used on the "understanding" it would be in connection with the Government's police recruitment drive and had "no prior knowledge" that the speech would veer into politics.
Mr Johnson has faced widespread condemnation for using lines of student officers as part of a "political stunt" criticising the Labour leader and referencing the general election the Prime Minister has failed to trigger.
Some 35 officers were positioned behind his lectern for at least 20 minutes before the speech at West Yorkshire Police's operations and training complex began, and during the address one became unwell.
In a statement on Friday, Mr Robins said: "It was the understanding of West Yorkshire Police that any involvement of our officers was solely about police officer recruitment. We had no prior knowledge that the speech would be broadened to other issues until it was delivered."
He said that "minutes before the speech" he was told that a scheduled visit to an National Police Air Service base had been cancelled, as well as a briefing to a pool of journalists.
"I was therefore disappointed to see my police officers as a backdrop to the part of the speech that was not related to recruitment," Mr Robins continued.
Shortly before Mr Robins' statement was released, Downing Street was defending Thursday's visit to the police facility in Wakefield.
"The PM's long-planned visit was highlighting a national recruitment campaign for 20,000 new officers which has been welcomed across the police service," a Number 10 spokeswoman said.
"It gave the PM yesterday an opportunity to see first-hand the outstanding training which new recruits receive and to meet those who have committed their lives to keeping us safe."
But shadow policing minister Louise Haigh was among those demanding an apology.
"The Prime Minister and his aides deceived the police by knowingly using officers for a naked party political stunt, without their prior knowledge," she said.
"This is a serious breach of trust and the Prime Minister should be ashamed of putting serving officers in this intolerable position. He should apologise to them immediately."
Police Federation of England and Wales chairman John Apter said he was "surprised" at the use of the officers in a political speech.
He said it was the "wrong decision" and that it was "disappointing" to see the focus taken away from the recruitment of 20,000 officers