A former Irish ambassador has predicted David Cameron will secure the reforms he has requested from the European Union - but questioned whether it will be enough to keep Britain in the EU.

The Prime Minister has pledged to campaign to keep Britain in the EU if he secures the reforms he has requested.

However, Daithi O'Ceallaigh, chair of the UK Project Group, Institute of International and European Affairs and former Irish ambassador to the UK, questioned whether a reformed EU "will have a really positive effect on the populus".

He said there has been a resurgence of "English nationalism", with critics likening Mr Cameron's reforms to the Munich Agreement with the Nazis in 1938, in which Neville Chamberlain returned with a piece of paper and declared "peace for our time" shortly before Britain declared war on Germany.

Speaking at the Scottish Parliament's European and External Relations Committee, Mr O'Ceallaigh said: "The Irish government will be as helpful as they possibly can because the Irish government wants the United Kingdom to remain in the European Union.

"I think David Cameron will be successful in the negotiations.

"There are a couple of difficult areas. The treatment of workers is a difficulty. It will be difficult to get down on paper a satisfactory relationship between the eurozone area and the non-eurozone area, although there haven't been any difficulties and it has worked reasonably well up until now.

"I think the questions of the powers of national parliaments versus the European Parliament will be a bit difficult as well, but I do think he could end up and will end up with a successful negotiation.

"But I wonder is that the question?

"It seems to me as an outsider, but an outsider with a long relationship with the UK, that it's much more cultural, historical, to some extent even emotional.

"I'm not talking about Scotland or Wales, and I'm certainly not talking about Northern Ireland, I'm talking about England.

"There seems to be a resurgence in emotional terms of some sort of English nationalism.

"So, even if he gets a successful outcome, and I think he will get a successful outcome, those who are arguing against continued membership of the EU have already written that off.

"They're talking about coming back from Munich with a bit of paper.

"I do think the Europeans will do everything possible to bring about a successful outcome for that negotiation.

"Whether that will have a really positive effect on the populus, I don't know."