According to the Standing Orders of the House of Commons, as I was saying earlier, if the Prime Minister asks for prorogation before advising the House of Commons, procedural consequences must ensue. However, legally speaking, it must be stated that the Prime Minister is expressly prohibited from asking the Governor General to prorogue Parliament without having given notice to the House of Commons. That is clearly set out in the legislation. Then, there is the problem of knowing what the court will decide.
On April 27th, 2010. See this statement in context.