A row has broken out between Merton's political parties after work to extend a vital bus route was delayed.

The S1 bus route between Banstead and Mitcham via Sutton and St Helier, is set to be extended by Transport for London (TfL) to serve the Lavender Fields area in Mitcham running from Upper Green East to Victoria Road via London Road and terminating at Fairfield Close.

The changes will bring an extra 700 households within 400m of a bus stop, help close a long standing "hole" in public transport in one of the most deprived areas of the borough and increase the frequency of buses along the route from three to four per hour.

The new route was due to start operating from November but has been put back to March 2014.

Opposition Merton councillors claim the delay is due to Merton Council's failure to make the necessary changes to the road layout in time.

Councillor Maurice Groves, Conservative member for Lower Morden ward, said: "I am astounded that by dragging its feet on this issue.

"Merton’s Labour administration is making residents wait another four months for this much-needed local bus service.

"Yet at the same time, they will happily spend over £500,000 on plans to drive a bus lane through the centre of Fair Green that many residents do not even want."

However Labour Councillor Mark Allison, ward member for Lavender Fields, said extended consultation on the location of bus stops was the cause for the delay.

He said: "Labour councillors have led the fight for this new service for a long time, and we’re delighted to have had this success.

"To be honest, until the Conservatives sent out a press release, nobody knew they were interested in the S1.

"If they had been involved, they would know that local residents want to have their say on the location of bus stops.

"We’re pleased that now the route has been approved a further survey will take place about that, and once it’s finished we can’t wait for the service to begin."

To see TfL's detailed plans and consultation results go here.