JACK Straw today admitted he had taken advantage of a new type of "freebie" for MPs.

The Leader of the Commons and Blackburn MP, received a free upgrade on three international British Airways flights for himself and his family.

The growing trend for free upgrades has been revealed in the Commons register of MPs' interests.

MPs from all parties, including Gordon Brown, Tessa Jowell, Liam Fox, Sir Menzies Campbell, Charles Kennedy and Keith Vaz, have declared they benefited the first time the perk has appeared on the register.

Today Mr Straw thanked British Airways and said: "They were gratefully received. They were standard space available' upgrades to use seats that would otherwise be empty.

"I don't know how they were arranged. Details of my flights official and private are always arranged by others. It's standard practice. Lots of people get them."

Former Foreign Secretary Mr Straw, his civil servant wife Alice and student daughter Charlotte, were upgraded from World Traveller Plus to Club Class by British Airways on a flight from Johannesburg to London.

And last summer the same airline upgraded him and his spouse to Club Class from London to Boston and to first class on their return.

A British Airways spokesman said: "We do not have a policy of upgrading MPs automatically."