London's 33 councils should be abolished and replaced with as few as five New York-style boroughs, Chartered Institute of Public Finance and Accountancy boss Rob Whiteman has suggested.

In a message delivered at today's London Summit for the capital's councillors and officers that he predicted would go down as well as a ‘bucket of sick,' Mr Whiteman said elected mayors across the country should be given the power to reorganise local government.

Mr Whiteman, a former chief executive of Barking & Dagenham LBC, admitted he had privately made the suggestion to the Department for Communities and Local Government that there were too many London boroughs. 

He said: ‘We don't need 32 London boroughs. Probably London boroughs are too big to be local and too small to be strategic.

‘London has had its footprint for 50 years. London will grow and it's had its existing footprint for a long time.

‘I do think it's time to change this. It would be better to help with engagement. Lots of the economies with which you are dealing don't make sense.'

However, Labour's directly elected mayor of Hackney LBC, Philip Glanville, tweeted that slashing the number of boroughs went ‘against times where place and authenticity are more important than ever'.

Mr Whiteman also said finance directors should be ‘gloomier' because those councils ‘getting near to the brink' had often been too optimistic.

He continued: ‘I don't see any easy solution to your finances, folks, in the next few years. My advice to many councils is not to be over-optimistic.

‘Your budgets are going to remain incredibly tight. If you're living in a very tight environment working with health is very important but I think we have to acknowledge that the NHS is not going to be the solution to your finances. I'm afraid there's no easy solution on adult social care pressures.

‘We had all expected that something would be done about social care [in the Autumn Statement]. Social care in many places – not all – is in crisis and about to fall over. 

‘Social care, I think, is a real problem. I suspect that in the lifetime of this parliament the chancellor will have to put more money into social care.'

On 100% business rates retention, Mr Whiteman predicted there would inevitably be ‘winners and losers' in the new system.

He added: ‘The fairer you make it by sucking all the money in and redistributing it according to need the less localist it is.

‘I think the design of the new system will be more localist than fair. I imagine there will be a massive row over redistribution.'

Appearing alongside Mr Whiteman, chair of the RSA's inclusive growth commission, Stephanie Flanders, argued it was ‘too late to be pessimistic about Brexit'.

She suggested councils' knowledge of place could give them ‘more leeway' in Whitehall post-Brexit.

Ms Flanders continued: ‘I think a lot of people in Whitehall are frightened of place. They have no idea what it means to be in touch but they do realise they are out of touch.

‘If Brexit has done anything it has put the human aspects of growth at the forefront of people's minds.

‘However, with all this talk of inclusion, don't forget the growth part. Everything is better with growth.'