The Liberal Democrat leader says in an election interview with ZEE TV, a satellite and cable channel that specialises in Asian affairs: "There are those in the Conservative Party, including some rather high-profile figures, who have talked about playing the race and asylum card.
"It may deliver them votes but it could unleash the most unholy consequences. There is a role for politicians to lead and set examples.
"If they duck out on this issue then they will find the issue devours them, instead of them being able to be the instrument that stops it."
But in a separate interview to be broadcast later this week, John Major goes out of his way to defend Nicholas Budgen, successor to Enoch Powell in Wolverhampton South-West, who has taken a leading role in opposing any further relaxation of immigration law.
Mr Major said that Mr Budgen's views had been misunderstood. "Like me he sees a place in the Conservative Party for people of different ethnic backgrounds," the Prime Minister said.
Told that the Tories were not seen as "Asian friendly", Mr Major said: "I am sorry if some Asians feel that, because it certainly isn't true. The Conservative Party is open to everyone whether they are Asian, British, Chinese or Caribbean. If they think like a Conservative and share the Conservative philosophy they will be welcome in the party. Asians make a huge contribution to the UK and I would like to see more Asian MPs."
He said: "The Asian culture and other cultures have sunk deep into the British way of life ... The old shibboleths and fears that people raised have gone and people now work, cheek by jowl, with Asian neighbours."
But a survey to be published in London's Time Out magazine tomorrow suggests that hardly any black Londoners believe Mr Major is sincerely concerned about the issues affecting them.
The survey found that only 2.5 per cent of those who responded thought he was concerned, and one-quarter of the 18- to 35-year-olds believed that he may even be a racist. More than half of those in the Time Out survey were not registered to vote and of those who were, one in five said that they would not be voting on 1 May.