**China’s top negotiator on Taiwan affairs is due to arrive in Taipei for trade talks that some fear could undermine the island’s sovereignty.**Ahead of the talks, tens of thousands of protesters rallied against Chen Yunlin’s visit.
The two governments hope to sign the free-trade pact by early next year.
The visit comes as Taiwan debates how close a relationship it wants with its former rival China, which still claims the island as part of its territory.
Unification concerns
On Sunday, up to 30,000 demonstrators marched through the city of Taichung, where the talks are to be held, chanting independence slogans and waving anti-China banners, police said.
Mr Chen is due to hold five days of talks on the proposed Economic Co-operation Framework Agreement (ECFA).
It is the fourth round of talks since China-friendly Taiwan President Ma Ying-jeou took office last year.
The BBC’s Cindy Sui in Taichung says critics fear a free-trade pact will flood Taiwan with cheap Chinese products, cause massive job losses, and undermine the island’s sovereignty by making it too economically dependent on China.
The government, however, says Taiwan will be marginalised by China in global trade if it does not sign.
Taiwan and China have been governed separately since the end of a civil war in 1949.
Taiwan’s opposition Democratic Progressive Party - which supports formal independence from China - made huge gains in local elections earlier this month.