The government has accused Michael Howard of cynical opportunism after the Tory leader spent yesterday campaigning on cracking down on illegal Gypsy and traveller camps.

Howard insisted that he is standing up for fair play and the rule of law on Gypsy camps.

"People claim it's racist to raise this issue. It is not, it is nothing to do with race. It is about standing up for the right values," he told reporters.

Labour MP Kevin McNamara begged to differ, warning that the Tory plans had "the whiff of the gas chamber about them".

Labour's election coordinator, Alan Milburn, accused Howard of "riding shotgun on the latest bandwagon to roll into town".

He was supported by the Liberal Democrat spokesman, Ed Davey, who called it the "height of hypocrisy" from a politician who had "done most to reduce the number of legal traveller sites" when home secretary in 1994.

Trevor Phillips, chairman of the Commission for Racial Equality, said: "This will only be a race issue if people want to make it one... it really should be about space and housing, not ethnicity."

Later, junior minister Yvette Cooper revealed that last summer both main opposition parties had agreed to try to find a cross-party consensus "to avoid escalating community and ethnic tensions" - only to see the Conservatives "jumping on the bandwagon" launched by newspapers such as the Sun.

"Shrill words about problem sites are useless if you are not prepared to address the root of the problem itself," she said.

Labour's answer is "more appropriate sites and swifter enforcement", she insisted.

Today the Conservatives will continue their populist campaigning.

Peter Lilley, the former Cabinet minister, will reject claims that the country benefits from sustained immigration, and the shadow environment minister, Tim Yeo, will promise to "prevent any commercial planting of GM crops" unless or until it is safe.