Party of European Socialists (PES) leader Sergey Stanishev on Sunday said Europe will be able to go forward with some integration initiatives more confidently than before as the UK is to leave the European Union.

He added that until now, London had vetoed a number of EU initiatives that could now be unblocked.

What the world witnessed in Britain over the past months is "politics at its worst," he told the Bulgarian National Radio.

"Cameron opened Pandora's box which in the end cost him his head. He will go down in history as the man who deeply divided the United Kingdom, with severe repercussions on Britain itself," he opined.

Stanishev, also a former Bulgarian Prime Minister and ex-leader of the Bulgarian Socialist Party (BSP), argued Europe could now take three paths, one of the "status quo" of conservatism, one of nationalism, and that of socialists who could address "the people's feeling there is no justice and they don't matter."

The debate about the future of Europe should not be about "more or less Europe", but the issue of "what Europe" is desired should come first, in his words.

In another interview, with daily 24 Chasa, published on Monday, Stanishev voiced his optimism that the EU would survive after Brexit and will go on with its mission to deliver stability and prosperity.

However, he blamed the "right-wingers" for the austerity policies that brough "irreparable damage" on the EU's nature and core values, turning Social Europe into a "myth"

He also downplayed the possibility of an in/out referendum taking place in Bulgaria. "There is no ground for Euroskepticism. The benefits of our membership are tangible."

Even though the EU did not increase the wealth of Bulgarians, many of these work, study or travel in the EU, "while our country as at the table of leaders in Brussels, takes part in the important decisions and receives EU funding."