Tony Blair has slammed the Conservatives as "absurd, laughable opportunists" and criticised their plans for reform of immigration and asylum policy.

In an article for the Times on Monday the prime minister said that the to draw opponents into accusing the party of racism, so that they could then protest it is not racist to discuss an issue of such importance.

Blair said the Conservative tactics make their opponents seem politically correct, but the Tories score points for "being honest", without anyone paying attention to whether the their plans have any prospect of working. 

He added: "What Britain needs is a set of immigration and asylum rules in the interests of Britain: strict controls that work."

"The reason immigration and asylum policy is difficult is nothing whatsoever to do with political correctness," Blair said.

"It is because the challenge of immigration and asylum is immensely complex. Every wealthy country in the world has it. Wholly contrary to the propaganda, Britain is not the asylum capital of Europe, let alone the world.

"All countries suffered a sharp increase in applications in the late 1990s, but since then they have fallen faster in the UK than elsewhere in the EU and monthly applications are now almost back down to spring 1997 levels."

Asylum

With the Tories pledging to withdraw from the UN convention on refugees, the prime minister said there is nothing in the treaty which stops the UK rejecting unfounded asylum claims.

The problem is that asylum is not claimed until the individual arrives here, Blair claimed.

"The best way to keep numbers down is to do all we can to keep those posing as refugees from arriving in the first place through tougher border controls; to process claims quickly as we are doing; and to speed-up the process of removals by making the destruction of documents a criminal offence and then securing returns agreements with the relevant countries," he said.

"Meanwhile, genuine refugees we should always find room for. This nation is proud of its tradition in doing so."

On controlled migration, Blair said that the system is beneficial to Britain and warned that shutting it down would be irresponsible and deeply damaging to our economy.

But he acknowledged there is abuse of legal migration with, for example, students applying for non-existent courses and people coming to work and then refusing to go back, or then switching to claim asylum.

"So what we need are strict controls that work. And that's what we have been putting in place. Compiling a register of universities and colleges that are genuine," he said.

"Stopping people switching categories for false reasons. Tightening up work permits so that only people Britain needs come in.

"The Conservatives' arbitrary quota - the size of which they can't say, even approximately - is not sensible. It may be too high or low and parliament can't possibly guess what the future will bring," he added.