The Mayor of London has given his initial support for a controversial expansion of Dundonald Primary School in Wimbledon.

The office of Boris Johnson responded to Merton Council this week giving his initial support to the application subject to three amendments to ensure the plan complies with the London Plan which sets out the economic, environmental, transport and social development framework for the capital to 2031.

Changes include agreeing hours of community use of the games area during school hours, ensuring excess rainfall is drained and collected effectively and installing more cycle parking spaces.

The council applied to the Mayor of London’s office to decide if the decision should be taken out of Merton’s hands as the plans involve building on open public space - contrary to planning regulations.

However it was decided by the Mayor’s office Merton Council should rule on the decision.

Members of the Protect Dundonald Rec campaign group have attacked the expansion for jeopardizing parkland for the sake of "questionable" financial gain and have suggested the council should build a new school on another site. Councillor Martin Whelton, cabinet member for education, said expansion is vital and will allow the council to provide primary school spaces to an additional 420 children.

He said: "We are experiencing a 39 per cent increase in the number of children needing good quality education near to where they live.

"This is a significant rise and our wish to educate locally is reasonable and in line with government policy."

The revised plans were expected to go before the planning committee on January 17.

However the council said it will now go before the planning commitee "in the first half of 2013", before returning to the mayor for the final decision.