BRUSSELS - Britain is demanding fundamental reforms on the European Union (EU), challenging the bloc’s core principles. After the EU leaders’ first discussion on the demands in details at a summit, London triumphed that “significant progress” has been made and “a pathway to an agreement” emerged.

The EU leaders softened their tones on British Prime Minister David Cameron’s demands after Thursday’s dinner during which leaders at the first time held “frank” talks on the details of British requests.

Cameron in November set out four-area demands of reforms on Brussels, among which to some member states, three were “supportable” but one was heavily criticized as “unacceptable” that London sought four-year benefit curbs of European immigrants in Britain, making it a sticking point of the summit.

Following their “substantive and constructive” debate, “significant progress” has been made, European Council President Donald Tusk told a press conference Thursday night, adding that he was “much more optimistic” after the dinner.

“We had an open discussion yesterday, especially on the U.K.’s request to limit access to benefits to people who’ve worked for four years,” said Belgian Prime Minister Charles Michel Friday morning on his arrival for the second day of the summit.(Xinhua)