Former British Prime Minister David Cameron on Thursday said that there is an 80 per cent chance that his country will quit the EU on the basis of an agreed deal and it might opt for a "soft Brexit" by staying close to a single market.Cameron's comments came at the annual General Meeting of the Indian Chamber of Commerce here. He said there were treaties after treaties and a series of changes after the UK joined the EU and it became a political union.Speaking on the impact of Brexit on the economy, he said there existed essentially two possibilities -- either to stay close to the European market and keep some of its rules intact or to be totally separate by making own rules."It depends on what sort of Brexit it is. If it is a Brexit where we remain allied to single market or somewhere, I don't think the impact will be huge," Cameron said.But he also said the 'harder Brexit' would create more friction.Cameron, who was Prime Minister from 2010 to 2016, demitted office after the referendum on leaving the EU as he strongly favoured staying within the bloc.He said it was better to stay within and fight for one's interests. "I think it (Brexit) is sub optimal (solution)."According to him, the backlash against market economy and rise in strongman politics are threats to global economy.Criticising US President Donald Trump's viewpoint on trade deficit, Cameron said the fundamental flaw in his thinking was that having trade surplus with everyone was good and trade deficit with everyone was bad.He wondered if everyone was in surplus, then who would have trade deficit.