Some 1,400 laid-off state workers have protested against corruption and unpaid benefits in north-eastern China, just days before the ruling Communist Party holds a key congress.

More than 1,000 workers who have been fired or face lay-offs from metal and textile factories protested in the city of Liaoyang in Liaoning, a Hong Kong rights group said.

And another 400 brewery workers demonstrated in Jilin's provincial capital, Changchun, according to the group - the Information Centre for Human Rights and Democracy.

The protests came as senior Party officials gathered in Beijing to approve a new leadership line-up to be unveiled once the 16th Party Congress opens on Friday.

Party debate

The gathering, reported to be taking place at the Jingxi hotel, is also set to give its blessing to a proposal to enshrine President Jiang Zemin's political theory - the "Three Representations" - into the country's constitution.

This effectively recommends that the Party's support base is expanded to include private entrepreneurs.

Party leaders are also expected to approve President Jiang's work report to be presented at the Congress, which reviews the last five years and outlines policy for the next five.

A whole new line-up of Chinese leaders is expected to emerge from the Congress. The most important change will likely see Hu Jintao take over from Mr Jiang as Party secretary-general.

Mr Hu is expected to take over as state president next March.

Mystery man

Mr Hu is something of a mystery both inside and outside China.

The BBC's Beijing correspondent, Adam Brookes, says that some see him as China's long-awaited political reformer, while others see him as a timid conservative who will emphasise continuity at the expense of bold policies.

It remains to be seen, for example, how he will deal with the simmering resentment by many workers against the reform of the beleaguered state-run enterprises.