The Tories said they were boycotting talks today on the future of elderly care - branding the meeting a "Labour Party political ploy".
Health Secretary Andy Burnham is joining charities, local authorities and care providers to discuss a national care service for England amid growing controversy over how the scheme will be funded.
But shadow health secretary Andrew Lansley said he was not taking part, accusing Labour of pursuing plans for a compulsory charge of up to £20,000 that could be levied on an individual's estate after they die - dubbed the "death tax" by the Tories.
He told GMTV: "(The talks are) a Labour Party political ploy.
"I will talk to anybody, anytime, anywhere, but I won't take part in a Labour Party political smokescreen that stops people making progress and covers up the fact that they are pursuing the option of a compulsory death tax."
Mr Lansley added: "We want to have a partnership between the state and individuals.
"We want to give people the option of taking out insurance so they don't have to sell their home.
"I want people to have the choice but the Government want people to be subject to their compulsory levy.
Mr Burnham called today's meeting after the acrimonious breakdown of talks with his Conservative and Liberal Democrat counterparts aimed at establishing cross-party consensus on the issue.
Labour detailed a range of suggestions last year on how the current means-tested system could be overhauled.
One of the options was a compulsory fee of up to £20,000 which could be taken from an individual's estate after death.
In a letter to conference participants, Mr Burnham acknowledged that all funding options had their "pros and cons".
"A voluntary option gives people more choice and control but will not cover everyone. A compulsory option provides peace of mind and care free at the point of use when needed, but restricts choice," he said.
He said that all three main parties accepted that care costs could not be funded out of general taxation alone, and that individuals would have to make some contribution.
The Health Secretary is expected to be told at the conference that he needs to be clearer about how the national care service would be funded.
Mr Lansley has warned that a compulsory system would unfairly penalise families who chose to look after elderly relatives themselves, creating a "strong incentive" for them to push the burden of care on to the state.
He said there were around 700,000 people in England currently spending more than 50 hours a week looking after an elderly relative who might turn to the state if they were hit by a compulsory levy.
He warned it could push up the cost of the scheme - adding an estimated £3 billion to the £3.4 billion funding "black hole" which the Tories say already exists in Labour's plans.
"Hundreds of thousands of silent heroes, who care for their own family, would be hit twice over," Mr Lansley said.
"They have spent years of their life caring for their loved ones, but when that loved one passes away Labour's death tax would make them pay the state for care they never received."