David Cameron is facing renewed pressure over allowing gay marriage as a Tory grassroots group warned that he was alienating the party.
In a letter to the Sunday Telegraph, the Conservative Grassroots group expressed a "deep concern" about "the negative effect of the gay marriage Bill on both Conservative Party morale and electoral appeal."
But the chairman of Cheltenham Conservative Association said donations were fluctuating no more than usual, with donors more concerned fixing the economy than an issue which he believes will "fade into memory".
The letter called on peers to reject the the Marriage (Same Sex Couples) Bill, which arrives in the Lords today.
It survived a Commons backlash when 130 Tory backbenchers opposed the move.
In the letter, Robert Woollard, chairman of Conservative Grassroots, wrote: "It (allowing gay marriage) is alienating much of our core support while failing to attract new voters with under two years to go before the general election."
He went on: "Long-serving party members – many of whom have had the responsibility of bringing up children themselves – believe that the family lies at the heart of Conservative values. The golden inheritance of every previous generation, that has been lovingly handed down to us, is now being smashed on the anvil of 'equality and fairness'."
Meanwhile, former Tory Cabinet minister Lord Mawhinney said the advice the Prime Minister was getting was not "politically astute" and that Mr Cameron himself said before the election that he would not allow gay marriage.
He urged the PM to prioritise the economy and education, reflecting the priorities among grassroots supporters in the West.
Cheltenham borough councillor Andrew Chard, chairman of the Cheltenham Conservative Association, admitted one or two donors had been lost over the issue but stressed that he believed they would return.
Mr Chard told the Daily Press: "Donors leave and donors come back, but what we haven't experienced is a flood in either direction. In my own view, we are not losing donors and we're not gaining donors at any fast rate.
"Whether you approve of gay marriage or not is a matter of conscience and, in five years, time we will be wondering what all the fuss was about.
"I remember when it became legal to be gay and they thought the world was going to fall apart.
"Gay marriage is one reason (why donors have left) but, quite frankly, what most of our donors are concerned about is getting the economy right.
"If that happens, all these things will fade into distant memory."
