PLAID CYMRU yesterday accused Labour of pandering to rich voters in Middle England after a member of the Welsh Assembly Government said Plaid's new housing policy was based on "spite".
The row broke out as Plaid announced a set of measures aimed at delivering more affordable housing, which it says will form a major plank of its general election campaign.
Among the proposals is one that would allow councils to levy higher rates of council tax on second homes. At present second-home owners enjoy a discount.
Attacking the plan, the Assembly's Deputy Social Justice Minister Huw Lewis said, "This is yet another sign of an increasingly desperate, extreme and leaderless party retreating to the margins of Welsh politics. It is a housing policy based on spite.
"Labour in the Assembly is delivering on housing. We are delivering policies designed to improve access to quality housing and to make it easier for the elderly and disabled to remain in their own homes. Our social justice budget will increase by £150m over the next three years, with an extra £16m each year allocated to the social housing grant.
"Sadly the Nationalists believe that zealously punishing a single group of people will solve all of Wales' housing challenges."
But Elfyn Llwyd, Plaid's parliamentary leader, said Mr Lewis's stance was an insult to his own Merthyr constituents.
"Our policies, of which measures relating to second homes represent quite a small part, recognise the housing crisis across Wales.
"Last night I was speaking to a lady from Pontypridd who told me her three daughters have no chance of affording to buy a home of their own. This confronts many thousands of young people.
"Sadly Huw Lewis and his New Labour cronies are more interested in protecting the interests of peo- ple in Middle England who can afford two homes rather than helping the many people in his constituency who can't afford one.
"Measures like abolishing stamp duty for houses costing the average price would save many young people about £1,500."
Conservative social justice spokesman William Graham said the policies were "neither new nor radical".
"We need a wider consideration of affordable housing provision in Wales. We need to ensure more effective co-operation with the voluntary and independent sectors - they are equally aware of the challenges we face and seek to participate in developing a solution."
Peter Black, Welsh Liberal Democrat housing spokesman, said, "A 200% council tax on second homes will have little impact and may distort the housing market so as to penalise local people seeking to sell their home. Punitive measures will only create resentment and division."