PRIME Minister David Cameron has been accused of 'undermining the traditional family' by a South West Conservative MEP.

In a forthright letter to the Prime Minister, Giles Chichester says he is 'saddened and disappointed' by Mr Cameron's actions. The Euro MP describes as unfair an anomaly caused by the withdrawal of child benefit from those paying the 40% tax rate.

But the Government proposal to legalise gay marriage comes in for the strongest criticism by Mr Chichester, who describes it as 'a bizarre attempt to redefine marriage'.

He tells Mr Cameron: 'Why you have chosen to push the Stonewall militant gay agenda is a mystery to me because same sex marriage was not in your manifesto and so far as I can tell from friends in the gay community there is no majority within that minority in favour of trying to make same sex unions or partnerships the same as traditional marriage. Equal yes, same no.'

Mr Chichester says he supports civil unions or partnerships having equal rights to traditional marriage so far as property ownership, legal status, taxation and inheritance rights are concerned, but cannot agree that 'being equal must mean being the same'.

The MEP says the attempt to redefine marriage undermines and affronts the traditional majority to no benefit to the gay and lesbian minority and 'does not pass the reasonableness test'.

He writes: 'What you could do is ensure that equality of rights does exist and remedy a wrong that would not be solved by redefining marriage, namely the unfairness of property and inheritance rules for brothers or sisters living together in a household.'

Mr Chichester asks Mr Cameron to reconsider his position during the consultation period and to apply the 'tests of common-sense and reasonableness that are the safeguard of Conservatives'.

'Should this measure go through it will cause many Conservatives to question their loyalty to a party which is no longer supporting values inherent to the party,' he adds.

At the Conservative conference last year, Mr Cameron said consultations on legalising gay marriage were about equality and commitment. He said: 'Conservatives believe in the ties that bind us; that society is stronger when we make vows to each other and support each other.

'So I don't support gay marriage despite being a Conservative. I support gay marriage because I'm a Conservative.'

In his letter to the Prime Minister, Mr Chichester also criticises the decision to withdraw child benefit from taxpayers subject to the 40% rate of income tax, saying it penalises the traditional family model of one earner and one carer while leaving it possible for couples with nearly double the income to remain eligible.

'I support the principle that higher rate payers should relinquish this benefit but the anomaly makes it unfair and, in particular, unfair to traditional family units.'

He says in the 2010 general election manifesto the Conservatives promised positive recognition of families through the taxation system.

He tells Mr Cameron: 'You have so far failed to honour this promise.'