Britain issued a further five licences over the past decade for the export to Syria of so-called “dual use” chemicals, which can be used in the manufacture of weapons, it emerged on Wednesday.

However, Vince Cable, the Business Secretary, said that all of the licences predate the outbreak of the Syrian civil war in early 2011, and said he was “confident” that the exports were for legitimate commercial purposes.

Mr Cable has come under fire in recent days over two licences granted in January 2012 for the export of sodium fluoride and potassium fluoride to Syria. The licences were revoked in July 2012 after EU sanctions were tightened, and the Business Department has said that none of the chemicals were shipped out.

The House of Commons Committees on Arms Exports Control (CAEC) released a letter from Mr Cable detailing five further licences for sodium fluoride totalling 4,150kg (4.2 tons).

In the letter, the Business Secretary said: “In the light of the recent and shocking use of chemical weapons by the Assad regime in Syria, I asked my officials to determine whether any other licences for chemicals had been granted for Syria over the last ten years.

“They identified five other licences, all for sodium fluoride, issued in July 2004, September 2005, March 2007, February 2009 and May 2010 (for, respectively, 50kg, 2000kg, 50kg, 2000kg and 50kg).

Title of article: Britain issued five further chemical export licences to Syria