Kosovo President Fatmir Sejdiu announced his surprise resignation yesterday in a move that could hamper the start of EU-brokered talks between Belgrade and Pristina.

Mr Sejdiu resigned following a court ruling that he breached the constitution by keeping a party post while in office.

“I presented my resignation for the post of Kosovo president today... ,” the President told a press conference.

“I was convinced that keeping the function of the president of the Democratic League of Kosovo (LDK) without exercising it did not violate the constitution. The court had a different opinion and I respect the ruling,” he said.

In a decision published on Friday, Kosovo’s constitutional court said that Mr Sejdiu was in “serious breach” of the constitution by holding the posts of President of Kosovo and of the LDK.

A complaint against him had been filed by 32 members of Parliament.

Mr Sejdiu’s resignation comes as Kosovo is due to restart talks with Serbia about outstanding issues between the territories. Belgrade has never formally accepted the independence of its former province.

Kosovo declared its independence in 2008 and, despite Serbia’s fierce opposition, is recognised by 70 countries including the United States and the majority of European Union members.

Pristina was given a boost in July when the United Nation’s highest court, the International Court of Justice, ruled that Kosovo’s declaration of independence did not violate international law.

Earlier this month Serbia agreed to hold talks with Kosovo to try to pave the way for Belgrade and Pristina to eventually join the European Union.

It is unclear how the resignation of Mr Sejdiu will affect the talks but observers fear the uncertainty over Kosovo’s leadership could slow down the process.

There are also concerns it could heighten political tension between the LDK and its coalition partner, the Democratic Party of Kosovo of Prime Minister Hashim Thaci.