Police are taking more than an hour to respond to ‘significant’ 999 calls in two thirds of London boroughs, figures have revealed.

Callers are waiting as much as two and a half hours for police to arrive, with 21 London boroughs affected in the last six months.

The most serious 999 calls – classed as ‘immediate’ – must have police on the scene within 15 minutes.

Other serious calls – including hate crimes, traffic accidents, or when there is concern for someone’s safety – are often classed as ‘significant’, requiring a response within one hour.

But police are often failing to arrive in time, with outer London boroughs worst affected.

On average, the outer boroughs waited 88 minutes for a response to ‘significant’ grade emergency calls in April, almost half an hour longer than the Met target.

Barking and Dagenham, Harrow, Newham and Bexley were worst impacted, with Barking residents waiting two hours and 28 minutes for an answer to their calls on average.

Islington, Camden, Hackney and Sutton performed best, with police in Islington on the scene in just 38 minutes.

Across the board, responses to the most serious ‘immediate’ grade calls are improving, with all boroughs under the 15 minute response target for the last six months.

But Liberal Democrat assembly member Caroline Pidgeon, who requested the figures from the Mayor, said all targets needed to be met across the capital.

She said: “Calling the police after a hate crime, or a road collision and then having to wait so long for the police to arrive is not acceptable.

“In many cases there is also a real risk that valuable evidence or witnesses are lost if the police fail to respond to incidents within an hour. ”

Sophie Linden, Deputy Mayor for policing and crime, said: “These figures show police response times for immediate calls have been consistently within the Met’s target, but work still needs to be done in some areas to improve S-grade calls.

“I will continue to hold the Met to account to ensure they are doing everything possible to meet the target times for all calls. But it’s abundantly clear that crippling government cuts to the police budget have impacted on officer numbers at a time when the demand for 999 and 101 calls continues to rise.”