By Mark Davies BBC News Online political reporter

The same thing happened with omelette pans. Then there was a big rush on prunes.

Now trade justice campaigners are hoping the famed "Delia effect" can help highlight their demands for a shake-up of global trade rules.

Delia has added her voice to trade campaign

The TV chef is joining hundreds of other campaigners to take part in a marathon lobby of MPs this weekend.

The event is being organised by the Trade Justice Movement, a coalition of 40 groups.

It is hoping to get its message to all 659 MPs in their constituencies over 24 hours this Friday and Saturday.

The event, called Scale Up for Trade Justice, uses a pair of scales as its logo.

Rock star

Ms Smith, a supporter of Cafod, the Catholic aid agency, said: "I'm scaling up for trade justice on June 28.

"Thousands of people across the country will be bringing out their kitchen scales to symbolise fair trade for small-scale farmers around the world."

Events in at least 450 constituencies have been confirmed so far.

Campaigners say more than 12,000 people attended a similar event last year when MPs were lobbied at Westminster.

And they have also signed up Radiohead guitarist Ed O'Brien to back the effort.

He said: "Our politicians have failed to grasp what harm this government is doing by pushing for more and more free trade - without taking into consideration its effect on poor people and the environment.

Crucial

"We want to make sure every MP gets a clear message that British voters want the rules on international trade rewritten to make world trade work for the whole world."

The event has been arranged with a World Trade Organisation meeting in Cancun, Mexico in September in mind.

Cafod head of campaigns Alison Marshall said: "2003 is a crucial year for trade justice.

"Important decisions about international trade are on the agenda in Cancun; the lives of the world's poorest people and the environment are held in the balance.

"The UK government says it wants trade to help end world poverty.

"Yet the government is pushing for policies in the World Trade Organisation that are biased in favour of rich countries and the west's corporations. We want to put the spotlight on our government's hypocrisy."