MARK THATCHER made millions of pounds from Britain‘s huge Al-Yamamah arms deal with Saudi Arabia, signed in 1985 by his mother, Margaret Thatcher, when prime minister, it is alleged today.

The deal, involving more than pounds 20bn in sales of Tornado fighter-bombers and naval vessels, is believed to have been the largest in history, and the money Mark Thatcher is said to have made from helping to broker it – allegedly pounds 12m – would explain his sudden rise to conspicuous wealth.