In a letter to  
          The Times
, prominent figures including five former bishops say statements by church leaders give a false impression of popular feeling.
"We believe the Church has nothing to fear from... civil marriage for same-sex couples," it says.
"It will be for the churches to then decide how they respond pastorally."
A leading signatory of the letter is Dr Jeffrey John, the openly gay dean of St Albans, whose appointment as Bishop of Reading in 2003 was withdrawn after protests from conservative Anglicans.
It is also signed by the suffragan bishop of Buckingham and the deans of Portsmouth, Norwich and Guildford.
It says marriage is a "robust institution which has adapted much over the centuries" and has "moved beyond the polygamy of the Old Testament and preoccupation with social status and property in pre-Enlightenment times".
Plans to legalise gay civil marriage by 2015 have been put out for consultation by the government, and under the proposal, same-sex couples will be entitled to convert existing civil partnerships into marriages, or get married in a register office or other civil ceremonies.
However, the plans maintain a ban on same-sex religious services, despite interest in them from some churches.
Leaders of the Roman Catholic Church remain staunchly opposed to gay marriage and blessing civil partnerships, but opinion among Anglicans has been more divided.
A group of leading Anglicans says the Church of England has "nothing to fear" from the prospect of gay marriage and it is should be a cause for rejoicing.