The Archbishop of Canterbury is to give a key speech to members of the Church of England's national assembly in York as attempts to restart talks over introducing women bishops get under way.
The Most Rev Justin Welby will give his first presidential address to the General Synod, at York University, as Archbishop of Canterbury.
The 57-year-old former oil executive and Bishop of Durham formally succeeded Dr Rowan Williams as head of the Church of England earlier this year.
His address comes as the General Synod attempts to restart talks over women bishops for the first time since the shock defeat of legislation in November.
Members will also be asked to approve a draft scheme to dissolve the three existing dioceses of Bradford, Ripon and Leeds and Wakefield.
Margaret Thatcher's death
The Archbishop of Canterbury said: "It was with sadness that I heard the news of the death of Baroness Thatcher and my prayers are with her son and daughter, her grandchildren, family and friends.
"It is right that today we give thanks for a life devoted to public service, acknowledging also the faith that inspired and sustained her.”
The Archbishop of York, has missed out on becoming the next Archbishop of Canterbury.
Dr Rowan Williams has been in the position as head of the Church of England for 10 years, but steps down at the end of December.
Dr John Sentamu had been a contender for the role, but the Bishop of Durham, Right Reverend Justin Welby, is expected to be confirmed later.