By Chris Hogg BBC News, Hong Kong

Mr Tsang is having difficulty selling his reforms

Hong Kong's chief executive has made an unprecedented direct appeal on television for people to support his proposals for democratic reform.

Donald Tsang used the broadcast on all local channels to sharply criticise the pro-democracy camp, which plans a mass rally against his plans on Sunday.

The government's constitutional reform package would make limited changes to the way the next leader is chosen.

But the plans do not meet the Democrats' call for universal suffrage.

The TV appearance was an unusual event.

Mr Tsang is still quite new in the job and if the opinion polls are to be believed, much more popular than his predecessor .

Timetable demand

But his efforts to get a package of constitutional reforms passed by the legislature seem to be faltering.

So he went on television to make his case directly to the people.

Beijing has told Hong Kong it does not think the territory is ready for universal suffrage. But Mr Tsang insisted his proposals would enhance significantly the way the next chief executive and the next legislative council will be elected.

Pro-democracy lawmakers disagree. They are demanding a timetable for the introduction of universal suffrage as the price for their support for what they argue amounts to little more than tinkering with an already undemocratic system.