The High Court has heard that if a general election is held anytime soon, the makeup of the next Dáil would be in breach of the Constitution.

Former Labour TD Joe Costello has been given permission to have his case on the issue heard tomorrow morning.

In the absence of some sort of miracle, it seems all roads are leading to a general election with most feeling it is a question of when, not if.

But Joe Costello is attempting to ward one off, at least for now.

The former Labour minister claims a newly-elected Dáil would be unconstitutional unless legislation on changes to constituency boundaries is passed, changes which include an extra seat in his own.

Due to an increase in population, as recorded in last year's Census, the next Dáil must have at least 159 members.

Mr Costello explains why it is important to have the legislation passed before an election is called.

"Really what we're looking for is that we avoid a constitutional challenge later because it would be an absolutely appalling vista if in fact there was an early election without the legislation being enacted.

"So it is a serious matter, and matter of considerable public interest", he said.

Due to the possibility of an election on the horizon, Mr Justice Peter Kelly has fast-tracked the case and it is due to be heard on Tuesday morning.