Prime Minister John Key says he has had "a brief look" at dates for the 2011 general election, and the Rugby World Cup is going to make things a bit tighter than usual.

The tournament runs from September 9 to October 23. Elections are usually held in October or November.

"There will be a huge focus on both - at different times, I suspect," he said today at his post-cabinet press conference.

"I'm not rushing to work out the election date...but obviously I've had a brief look and it's fair to say there are more limited options in 2011 than there would be in other years."

An election before the World Cup was "very unlikely" he said.