Boris Johnson has pledged to retain a police commander for each borough after proposals to merge Barnet and Harrow’s top officers into one role emerged from a body he is in charge of.

A plan to create one borough commander for Harrow and Barnet, seen by the Times Series, is being considered by the Mayor’s Office for Policing and Crime (MOPAC) as the Metropolitan Police seeks to fill a £233milllion funding gap by 2015.

The Times Series understands that the current borough commanders for both Barnet and Harrow have been briefed in detail about the plan, which has also been circulated to local authorities.

But after being presented with a map showing the proposed mergers at Mayor’s Question Time last week, Mr Johnson claimed he did not know of the plan, despite being the head of MOPAC.

London Assembly Member for Brent and Harrow, Navin Shah, and his Barnet and Camden colleague Andrew Dismore, have written to the Mayor to state their opposition to any plan to merge borough commanders and accused him of being “undemocratically reluctant to discuss it”.

Mr Shah added: “Both borough commanders have told us that they [MOPAC] are planning to merge it – and I have formally written to MOPAC registering my objection to such a merger.

“We will be left without leadership at local level and Harrow has very good public partnership and community cohesion that has come about through local police engagement – that will be eroded with a joint borough commander.

“Harrow and Barnet are two very large outer London boroughs that have very different issues and approaches – that focus will be completely lost.

“Quite frankly it is bad news and good work in local policing over a decade is at risk.”

The Met has already planned £537million of cuts to its budget as it tries to reduce the biggest deficit of any force in the country.

But in response to questioning about the proposals, which suggest cutting the number of commanders from 32 to 25, Mr Johnson accusing Labour Assembly Members of “scaremongering”.

He added: “I’m not aware of any proposal to merge borough commanders – although where you can economise on policing budgets by sharing services across boundaries I’m more than happy to look at it.

“People are perfectly entitled to come up with all sorts of proposals but it is my view that there should be a single figure at the top of every borough who is directly and immediately accountable for policing in that borough – that is the borough commander.”

The Mayor’s office said it did not wish to add to Mr Johnson’s comments.