The Spanish Government today launched a major diplomatic effort to stem the tide of African migrants sailing to the Canary Islands.

More than 600 people have been caught attempting to reach the Spanish archipelago in crowded fishing boats in the past 24 hours, the largest number reported in a single day so far.

Many, including several small children, were suffering hypothermia and exhaustion from the 950-mile voyage which takes at least five days.

Madrid was forced into action today as the number of migrants fleeing sub-Saharan Africa continued to escalate: more than 7,000 have arrived on the shores so far this year, five times more than in the same period in 2005, and the calm seas of early summer led to a rapid acceleration in numbers.

The surge follows a crackdown on shorter, safer routes across the Straits of Gibraltar. Red Cross figures suggest that around one in five drown making the journey.

Spanish authorities have already stepped up surveillance in the area, using satellites, Navy planes and ships to track and intercept the little boats.

At the weekend, a team of ten diplomats will begin a six-month tour of countries along the coast of West Africa to persuade local authorities to step up their own controls and to accept more deportees. They will visit Gambia, Cape Verde, Guinea Bissau, Guinea Conakry and Niger.

The Spanish Cabinet is also expected to approve the immediate sending of an ambassador to Mali, whose nationals make up a large proportion of the illegal immigrants.

Jose Luis Rodriguez Zapatero, the Spanish Prime Minister, has faced repeated accusations of being soft on illegal immigrants: Spain was the biggest immigration destination in the European Union last year and 60 per cent of citizens believe there are too many migrants.

The Prime Minister declared on Wednesday that the situation had become a humanitarian crisis and had become a problem for the entire EU.

The diplomatic offensive will run alongside a three-year Africa Plan through which it is trying to raise more EU aid for Western Africa to create job opportunities in the sub-Saharan countries.

Senor Zapatero has also pledged to increase the rate of deportation of migrants who do not meet asylum requirements. Those from countries with no deportation agreement with Spain, or without proper identification often avoid repatriation.

Their fate is usually to wait 40 days in a packed reception centre before, if their home country can not be established, they are released under Spain's liberal immigration laws. Without papers, many find work in the black market selling counterfeit goods on the streets.

“It’s worth the risks, there’s no way you can stop people coming,” Tal, a Senegalese who sailed to the Canaries and now sells pirate CDs in Madrid, told Reuters.

Red Cross workers on the Canaries say they are overwhelmed with the "avalanche" of people arriving every day, many of whom are in need of immediate medical treatment.

Officials on the Canaries said that of the new arrivals, 249 Africans without identity papers had reached Tenerife island, 177 had landed on El Hierro and another 178 had reached Gomera island.

Jose Miguel Ruano, a member of the Canary Islands government, told Reuters that the situation was out of control. "The Spanish Government has not met its commitments," he said.

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