Lewisham Council has been accused of letting down some of its youngest residents after league tables showed the borough's schools had the worst GCSE results in London.

According to controversial tables released last week, only 51 per cent of the borough's GCSE pupils managed five or more A* to C grades including English and maths last year - the benchmark measurement for school standards.

That figure makes Lewisham the worst of the capital's 32 boroughs, with other inner London areas like Newham managing 55 per cent and Hackney on 58 per cent.

Duwayne Brooks, who ran to be Mayor of Lewisham at the last election, said the results showed the council was failing teenagers.

He said: "The people in Lewisham are being let down. It's 51 per cent across the board. Last year it was 56 per cent.

"It's down to a lack of leadership, as always."

Across the country the number of under-performing secondaries doubled this year, with many headteachers warning that constant reforms were badly effecting the country's poorest pupils. Calculations by the Teach First charity also reveal that the attainment gap between rich and poor students has widened this year.

Meanwhile, the Department for Education has insisted that the rise is down to two key reforms - a decision that only a teenager's first attempt at a GCSE would count in the annual performance tables, and a move to strip poor quality vocational qualifications out of the rankings.

But Peter Fortune, Tory parliamentary candidate for Lewisham East, said: "There is an argument to be made that harder exams and restrictions on retakes has meant that fewer students have been able to make the grades that they want, but despite this it is clear that Lewisham is under performing when compared to neighbouring boroughs. 

"Lewisham Council is almost entirely represented by Labour councillors and I think it is time that they take responsibility for this slip in standards."

Cabinet member for children and young people Councillor Paul Maslin said: "We had already identified secondary school attainment as a key priority, which is why in our manifesto we pledged to increase results significantly during our term in office. There is no reason why our young people can’t achieve as well as others in London.

"Our schools are as determined as we are to quickly and significantly improve results for our young people and we have been challenging and supporting them to do so. We won’t hesitate to take decisive action if necessary to ensure that is the case."

The news comes as local National Union of Teachers members from five schools announced they intend to strike on February 12 in a continuing row over the number of secondaries becoming academies in the borough.