Four in ten jobs in Chingford and Woodford Green pay less than the living wage, according to the TUC

The benchmark income, which is calculated on the cost of living in the capital but is not legally binding, is currently £8.80.

The TUC claim 43.4 per cent of jobs in Chingford and Woodford Green pay less than the living wage, compared to a national constituency average of 20 per cent.

Mr Duncan Smith’s office says his commitment to fair wages is beyond doubt.

The research was said to be based on an analysis of figures from the House of Commons library as of April 2013 and also found 35.5 per cent of women working in Walthamstow were paid less than the living wage.

Overall 28 per cent of jobs in Walthamstow paid less than the benchmark amount and in Leyton and Wanstead the figure was 22 per cent, according to the TUC.

TUC general secretary used the research to highlight the Secretary of State for Work and Pensions' statements about encouraging people on benefits to get back to work.

Frances O’Grady said: "Iain Duncan Smith talks a great deal about making work pay.

"However try telling that to the four in ten workers in his constituency who earn less than the living wage.

"Poverty pay is sadly becoming the norm for many Londoners. That’s why the government must take the lead and insist that companies who bid for public sector contracts in the Capital, and throughout the UK, pay the living wage."

A spokeswoman from Iain Duncan Smith’s office said: "Firstly, crucially, wages are a matter for the Deparment for Business, Innovation and Skills.

"He is responsible for employment, and we are currently seeing record levels of employment in the UK – accompanied by dramatic falls in unemployment and inactivity.

"Secondly, no one can doubt Iain’s commitment to fair wages. It was at his insistence that the Department of Work and Pensions became the first government department to pay the living wage, including all staff employed via contractors."