Extreme sports retailer Just Add Water is now selling Insure & Go's Scratch & Go travel insurance cards.

Insure & Go launched the cards in April this year and they have been available through 40 WH Smith airport stores and from major London train stations.

The cards provide comprehensive last minute insurance. For instant activation and cover, travellers scratch off the card's panel to get a validation code and then contact Insure & Go to activate the policy. Policies are underwritten by Travel and Personal Underwriters (TPU).

A leading travel insurance intermediary said he thought the cards were "going one step too far".

He said in order for such a scheme to work, the company needed a particularly large brand name.