Mrs Thatcher and Herr Helmut Kohl, the West German Chancellor, agreed last night that the most important thing for East Germany was the establishment of genuine democracy and a period of calm.

During a 20-minute telephone conversation, Mrs Thatcher told Herr Kohl that the scenes she witnessed on television were exciting and the most historic she had ever seen. It was ``a great day for freedom''.

Herr Kohl, who made the call to Mrs Thatcher at Downing Street, told her of his impressions of his stopover in Berlin. The two leaders agreed to keep in close touch over the next few weeks.

Earlier the Prime Minister had told reporters: ``I watched the scenes on TV last night and again this morning.

``One ought not only to hear about them, but see them because you see the joy on people's faces and you see what freedom means to them.

``It makes you realize you cannot stifle or suppress people's desire for liberty.

``I watched with the same joy as everyone else.

``I hope it will be a prelude to the Berlin Wall coming down.''

She emphasized that the important thing now was to proceed step by step and ensure that multiparty democracy was established in East Germany.

That had to happen before reunification of Germany could be considered.

Mrs Thatcher declared: ``None of this would have happened without the vision and courage of Mr Gorbachov, who started to enlarge liberty in the Soviet Union.''

She said East Germans would have to apply themselves to create genuine democracy. ``That is a very good stimulus to stay and take part and help to build it.''