“As this happens, the courts and police will no longer be able to detain criminals freely and legally,” the Prison Governors Association (PGA) said in an open letter to political leaders in the UK on Tuesday.

"This will put the public at risk as people who should be in jail will be left to roam the streets," the PGA said.

According to Xinhua news agency, the latest data released by the UK Ministry of Justice shows that the prisoner population in the country has reached 87,395, which is only 1,383 less than the total usable operational capacity.

On 15 May, the UK government launched Operation Early Dawn, delaying the start of some court cases across England.