Members of the group covering south east England have asked for membership of the Transport for London Board.

A government proposal to extend the mayor's powers is under consultation until May.

A spokesperson for the mayor said two members would have to be appointed to the board to "represent the interests of people outside London".

The South East England Regional Assembly (SEERA) is mainly funded by the government and is responsible for planning the region's transport infrastructure.

Around 70% of its members are local councillors.

SEERA chairman, Keith Mitchell, said: "The assembly needs to be involved in the decision making process where it can influence and look after the region's interests."

The spokesperson for the London mayor added that if powers were granted to the mayor over rail services beyond the Greater London Authority boundary then "under the Railways Act 2005 the mayor must consult the regional planning body before making any appointments".