Blair faces a fight on Friday

Britain is this week facing an uphill EU struggle over plans to link development aid to third world action to cut illegal immigration.

Spanish prime minister, Jose Maria Aznar, visits Downing Street today ahead of Friday's European summit in Seville.

The meeting comes amid a growing row over the UK's asylum proposals, which are opposed by a significant group of key EU players.

Foreign ministers from France, Sweden, Luxembourg, Belgium, Portugal and Greece have ruled out any plans to cut development aid or suspend trade agreements.

Opposition to the plans could result in defeat for Tony Blair, who has given high profile backing for the measures.

The prime minister declared it "politically imperative that Seville delivers a strong push" on the asylum agenda.

"We should ... be willing to use the EU's economic and financial clout with those (countries) which are not co-operating," he wrote to Aznar recently.

Following Monday's meeting of EU foreign ministers, Jack Straw repeated the call.

"We must send a powerful signal to some third countries that, if they want to develop a strong relationship with the EU, they must better co-operate in fighting illegal immigration and in taking back their own nationals," the foreign secretary said.

"This should be part of the EU's political and economic dialogue with these countries.''

The plans to cut aid to some of the world's poorest countries or make grants conditional on measures to halt migration are controversial amongst European governments - and face criticism within the UK.

Some EU countries would rather see an incentive-based system for countries who control migration - rather than punitive measures which could fuel poverty and immigration in the third world.

Under proposals tabled by Spain, which are backed by Britain, all new EU trade and aid deals with "relevant countries of origin and transit" will include a condition stipulating cooperation on immigration.

Under the proposals governments can suspend aid agreements if the third world country refuses to implement the clause.

If passed, the new rules would oblige countries to strengthen border controls, introduce domestic legislation to tackle "people traffickers" and force them to reaccept nationals deported from the EU.

Despite UK hopes that Jacques Chirac's new right-wing government would take a tougher anti-immigration stance, a French diplomat told EUobserver that sanctions are "not very useful, and definitely not efficient".

"We are for giving more operational and financial support to third world partner countries, and not threaten them with sanctions, if they do not do what we want," he told the website.

Belgium, Sweden, Luxembourg, Portugal and Greece have also expressed concerns.

"They do not want too much importance to be given to sanctions, as this could trigger the adverse effects: the population would feel penalised if sanctions are applied, and they would emigrate in even larger numbers," an official told EUobserver.

A decision to link aid to deportations is also likely to spark anger amongst Labour backbenchers and some ministers.

The international development secretary, Clare Short, recently attacked a leaked Downing Street paper which called on aid to Somalia, Sri Lanka and Turkey to be linked to the number of refugees they accept back.

Short said the idea was "not thought through and not sensible"."People say things like that without thinking," she insisted. "In terms of British aid, it is illegal, because under law we can only spend it for development."