LONDON – Conservative Party members in Britain have written to their leader, Prime Minister David Cameron, to urge him to delay a parliamentary vote on gay marriage.

The politicians warned that the ruling party will lose significant numbers of voters in the 2015 election if the plans enter law.

Lawmakers are due to get their first vote Tuesday on the proposed bill, which would enable same-sex couples to get married in both civil and religious ceremonies. It would also allow couples who had entered into civil partnerships to convert their relationship to a marriage.