Sadiq Khan visited Earlsfield's Burntwood School last week as part of Parliament Week.
The Tooting MP was shown school facilities that are being built as part of Labour’s Building Schools for the future initiative.
The Shadow Justice Minister campaigned for the school to retain its funding after the initiative was cut in 2010.
He met with members of the school council, which has two students from each school year.
Children presented the MP with letters they had written to him, asking that he support UNICEF’s climate change campaign.
They discussed issues such as giving the vote to 16 and 17 year olds, how politicians can engage young people in politics and what can be done to get more women into politics.
Mr Khan said: "It is important to engage with young people and to encourage them to think about the issues that affect them. I really enjoyed my visit to Burntwood, the school council is a real credit to the school."
Burntwood's state of the art buildings will be completed in 2014.
The council are now looking to arrange a tour of parliament as a follow up.