Tesco’s promise to create 20,000 new jobs by 2014 has been called into question by the Association of Convenience Stores (ACS).

The supermarket giant pledged to create 20,000 jobs over the next two years “through a significant investment in customer service, refreshing existing stores and opening new ones”.

Tesco UK CEO Richard Brasher said the announcement was “a huge shot in the arm for the economy”.

It is unclear whether these 20,000 jobs will be full or part-time positions.

But speaking on Radio 5 Live, ACS chief executive James Lowman called for proper scrutiny of job creation claims by major supermarkets. “I would urge people to take these announcements with a pinch of salt because we’ve been here before,” he said. “Tesco previously announced that between 2008 and 2011 they pledged to create 30,000 new jobs and it turned out they created less than 12,000 new jobs.”

In January, some of Asda’s job creation claims were called into question after official records showed the supermarket had not created as many roles as it had suggested.

It had pledged “30,000 job opportunities in the Asda team in 2011” but records at Companies House indicated its staff numbers had increased from 173,000 to 180,000, an increase of just 7,000.