Britain is currently receiving the highest number of immigrants in its history
UK politicians are "living on borrowed time" on immigration, a former Labour minister has said.
Frank Field questioned whether current record levels of migration into Britain were "sustainable".
And he told the BBC News website the UK was in danger of becoming a "global traffic station" for migrant workers.
He urged politicians on all sides to stop ignoring public concern on the issue before the BNP found a leader with the "talent" to exploit it.
The UK is currently receiving the highest number of immigrants in its history, following a surge in migrant workers from new EU member states.
When the EU expanded to 25 members in 2004 the UK, Ireland and Sweden were the only countries which decided not to restrict people from the new member countries - notably Poland - taking jobs.
At the time the UK government predicted 13,000 workers a year from the new EU member countries would move to the UK for work, but the actual figure of registered workers was about 329,000 in 18 months.
According to the latest available figures, for 2004, the overall migration picture saw 359,000 people leave the UK while 582,000 settled in the UK. The figures do not include illegal migrants.
Tony Blair's official spokesman distanced Downing Street from Mr Field, saying the MP "speaks for himself" and added that "you have to remember the great economic benefit of migration".
Mr Field, a former welfare minister, questioned whether this level of immigration was sustainable without "dramatic" changes to the character of the country and hitting poorer areas, which have to absorb migrants.
"This is the most massive transformation of our population. Do we just merely accept this as another form of globalisation? That it doesn't matter where you are, or that you belong to a country and have roots? That we are all just following the jobs?" Mr Field told the BBC News Website.
People who questioned mass immigration were often accused of "playing the race card" but, Mr Field argued, this was "just another way of closing down debate".
The Birkenhead MP added: "There will be economic gains [from immigration] but I am just raising whether any country can sustain the rate of immigration we are now suffering.
"If we are not careful, we will be transformed into a global traffic station and that is not what most people mean by being part of a country."
He added: "It is only because the BNP are so inept that the debate has not taken off."
He said mainstream politicians had to address immigration "before the BNP stumbles on somebody with talent".
"We are living on borrowed time. We can not continue on the assumption that the BNP will present leaders which turn off most voters, even if what they are saying is important," he said.
Tony Blair promised a debate on immigration after last year's general election but so far this had not materialised, added Mr Field.
And, he said, the Conservatives had stopped talking about the issue because they were trying to improve their image and "show they were up not up to their old tricks, whether the electorate want them to or not".
The Conservatives were asked to comment on Mr Field's remarks but have so far failed to respond.
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