For the first time in its history on Monday, the Church of England could vote to allow female bishops, ending half a century of bitter divisions over the role of women.
A yes vote by its governing body, the General Synod, could see the first women appointed to the Anglican Church's top jobs by the end of this year.
Although the idea of female bishops was rejected in 2012, senior church figures are hopeful it will pass this time after a careful reconciliation process involving figures who previously worked to bring peace to Northern Ireland.
Welby said there was a "good chance of the first woman bishop being announced very early in 2015, possibly been chosen before that".
If the move again fails to go through at the meeting in York, northern England, the Church of England could be set to take drastic action.
The Guardian newspaper reported last week that options to force change if necessary are being considered.
This could include bishops who sit in the House of Lords introducing legislation to allow women bishops without going through the General Synod.
A spokesman for the Archbishop of Canterbury said: "We are concentrating on getting the vote through. It would not be helpful to speculate further."
- 'Get on with it' -
Any move to let women take the top positions in the Church of England is fiercely opposed by conservative Anglo-Catholics, who believe that only men should be priests and bishops.
But some of those opposed to the measure have been involved in drafting the proposals which will go before the General Synod on Monday.
These include principles welcomed by conservatives, including a statement that the Church of England is committed to helping those opposed to women priests and bishops "to flourish within its life and structures".
Officials hope that such inclusive measures mean that the current package is more likely to pass than in 2012.
At that point, it was defeated by just six votes from lay representatives of the Church, drawing a shocked reaction from many.
Then Archbishop of Canterbury Rowan Williams said afterwards that the no vote meant the Church "lost a measure of credibility" in society, while Prime Minister David Cameron said he was "very sad".
The first women vicars were ordained in the Church of England in 1994 but the issue of women's role in the Church has been debated for at least 50 years.
"The time has come now to sort it out and get on with it," said Canon Jane Hedges, Dean of Norwich in eastern England, who is tipped as a potential future bishop.
"There are so many enormous issues facing our world and so much real need -- in a sense this distracts us and absorbs a lot of energy," she told AFP.
The Church of England is the mother church of the global Anglican Communion, followed by some 80 million people in over 165 countries.
There are already Anglican women bishops in countries such as the United States and Australia.
While a yes vote would not force Anglican churches in other countries to allow women bishops, senior clergy say it would send a powerful message which should prompt others to follow.
If the vote does pass, it would need to be debated by parliament, approved by Queen Elizabeth II and then come back to the General Synod in November as a formality before coming into effect.
Parliament would be likely to vote in favour of the measure if the General Synod had previously backed it and the first women bishops could be approved by the end of 2014.