Help Ireland or it will exit euro, economist warns

"This is war: countries have to defend themselves," said David McWilliams, a former official at the Irish central bank.

"It is essential that we go to Europe and say we have a serious problem. We say, either we default or we pull out of Europe," he told RTE radio.

"If Ireland continues hurtling down this road, which is close to default, the whole of Europe will be badly affected. The credibility of the euro will be badly affected. Then Spain might default, Italy and Greece," he said.