Frontline police are losing the confidence to use their full powers after lengthy prosecutions like the trial of the officer who shot Chris Kaba, the shadow home secretary has said.

Chris Philp told a policing conference in Westminster that if the Government does not bring in legal changes to give officers better protection he will bring proposals to Parliament himself.

He said: “Many officers I’ve spoken to … feel their reasonable use of force or other police powers is treated disproportionately or unreasonably after the event, in a way that doesn’t reflect and recognise the pressures of dealing with an incident or the split second decision making, which is inevitably required.

“Some incidents go into lengthy and bureaucratic Independent Office for Police Conduct investigations, or even prosecutions, where common sense says that is not appropriate.”

Martyn Blake was cleared of murder in three hours by a jury at the Old Bailey last month.

Mr Philp also cited the case of Pc Paul Fisher, who was cleared of dangerous driving after crashing on the way to a terrorist incident in Streatham, south east London.

We need police officers on the front line to be prepared to take the lawful action necessary to protect themselves and the public

“We need police officers on the front line to be prepared to take the lawful action necessary to protect themselves and the public,” delegates were told.

“We need them to drive quickly to the scene of an attack by terrorists and save lives.

“We need stop and search to be used to take knives off our streets, we need force to be used where necessary to detain suspects, and I’m concerned that officers are losing the confidence to exercise those powers as required to keep the public safe.”

Plans have been drawn up that would offer anonymity to firearms officers accused of murder over a shooting in the line of duty, and raise the bar for criminal charges used by a police watchdog.

Mr Philp said he wants the Government to allow officers to use the fact they were acting in line with their training as a defence to a criminal or misconduct charge.

“I believe that it should be a defence to both misconduct proceedings and also criminal proceedings, if an officer can show that the way they acted was following materially their training or standard procedures in the way they exercise their powers.

“I think that will really help give officers the confidence to use those powers.”

He went on: “If the Government doesn’t make those changes, then at the next opportunity, as the shadow home secretary, I will seek to introduce those measures as an amendment to the next piece of legislation that goes through Parliament.”

Mr Philp used the speech to tell police chiefs “you’re not the thought police” as he said officers should only be investigating non-crime hate incidents where there is a “real risk of imminent criminality” and that probes “should not trespass upon free speech”.

Amid a debate about how the incidents are handled by officers, he called on the Government to “urgently” re-write guidelines and urged forces to use “common sense”, adding that changes to the rules would help “rebuild confidence” in policing and free up time to spend on fighting crime.

The former policing minister, who began by proudly confirming he was wearing his signature “Union Jack socks”, also joked about his time serving under former prime minister Liz Truss as he took to the stage, telling delegates: “My time as policing minister in the Home Office were among the best years I spent in government.

“Now I know that did include a spell as Liz Truss’s chief secretary to the treasury, so the bar is not hugely high, but those years as police minister were definitely the best I spent in government.

“So, I’m looking forward enormously to my new role as shadow home secretary, and I certainly intend to work constructively with policing leaders, with police and crime commissioners, and indeed the Government in the national interest.”