Labour has announced it would build more prisons by allowing ministers to bypass the traditional planning process, if it wins the general election.

Under its plans, prisons would be designated sites of “national importance” on public safety grounds – placing the power to green-light planning applications solely in ministers’ hands.

The party said the policy would help it create the 20,000 prison places the Conservative Party has promised but not yet delivered.

The Conservatives attacked Labour’s record and said the government had overseen the “largest expansion to the prison estate since the Victorian era.”

Shadow justice secretary Shabana Mahmood said Labour’s proposals were designed to tackle “dangerous overcrowding” in UK prisons.

Labour said the situation meant fewer criminals were being arrested, court hearings were being delayed and criminals were being released from prison early.

The party also outlined proposals for “Employment Councils” encouraging prison governors to work with local employers to secure training and jobs for prisoners.

This would “drive down” reoffending, Labour said.

The Conservatives had promised to create 20,000 “modern and innovative prison places” by the mid-2020s.

But as of April this year, the Ministry of Justice said it had only delivered roughly 5,400 additional places.

Labour said its proposals would help create the remaining prison places – roughly 14,000 – to reach the Conservatives’ original target.

A spokesperson for the Conservative Party hit back against the plans, saying the last Labour government “let 80,000 criminals out early and failed to build the prisons they promised.”

Labour had also voted against government measures to provide “more resources for our police and tougher sentences”, they added.

The Conservatives were “delivering 13,000 new prison places,” the spokesperson said.

Last year, the Liberal Democrats called for “comprehensive” prison reform, including the improvement of rehabilitation services in prisons and a “presumption against” short custodial sentences.

The Green Party has said in the past it would introduce social policies to tackle what it considers to be the root causes of crime, such as poverty, inequality or drug addiction.