A petition urging the Archbishop of Canterbury to accept women and gay clergy in the Anglican Church is to be presented to the church parliament.
Dr Rowan Williams warns of a difficult time ahead
The 8,000-strong petition will be handed over to the parliament's bi-annual meeting at Lambeth Palace.
Last year, the Anglican church was plunged into crisis with a row over the ordination of a gay bishop in the US.
On Monday, Dr Rowan Williams told the General Synod the Anglican church faced "unprecedentedly difficult challenges".
'Conservative and puritanical'
The petition, signed by 8,000 "liberal Anglican" individuals and 100 parish councils, calls for a church "open to all, regardless of race, gender or sexual orientation".
It was due to be presented to a representative of Dr Williams at Lambeth Palace on Tuesday afternoon by the organisation Inclusive Church.
The liberal Anglican group was set up after the gay clergyman Jeffrey John was chosen to be the Bishop of Reading last year but agreed to stand down after pressure over his sexuality.
Inclusive Church spokesman Mark Vernon told BBC News Online: "The idea isn't just about people concerned about gay men and women in the church but is about a culture developing in the church which is conservative, puritanical and not inclusive.
"We think it's important that more mainstream voices in the church, which are the majority, are heard. People of a liberal spirit aren't always as well organised, or indeed as well funded, as the conservative voices."
On Monday, Dr Williams said that divisions over homosexuality were presenting the church with its most difficult challenge ever.
The General Synod, which runs until Friday, is due to debate homosexuality and legal recognition for "gay marriages" and other cohabiting couples later in the week.
The Anglican Church has seen bitter divisions since the ordination of gay bishop Egen Robinson in the US last year.
Bishop Robinson, a divorced father-of-two, was consecrated in New Hampshire last November amid protests from traditionalists.
An extraordinary meeting of Anglican leaders worldwide, also held at Lambeth Palace, warned his consecration could "tear the fabric" of the Anglican Communion.
Meanwhile, it was confirmed on Tuesday that Bishop Robinson will take part in a debate at the Oxford University Union over whether "a gay lifestyle should be
no bar to becoming a bishop".