Professor David Farrell:

It creates a tension. There was a recent instance where there was a discussion about the Greek situation in the European Council where various Ministers for Finance were talking about the need to get agreement from their parliaments before they could decide once and for all. In fairness to our Minister for Finance when he said that, most of us just had a wry grin on our faces because it was obvious that whatever the Minister might decide in our case would be the decision. So it would be a token gesture by the Parliament to try to suggest otherwise. However, in the case of some of the other Ministers that was a genuine concern they had.