New Delhi: "Pro-tem Speaker", a term seldom heard outside legislative circles and that too only briefly at the start of a legislature's five-year term, has become the new flashpoint in the ongoing battle for Karnataka.

The Constitution does not provide for a pro-tem Speaker, who is a temporary Speaker appointed to oversee the swearing-in of the newly elected members at the beginning of a legislature's term.

All that the Constitution says in Article 188 is that the President - in the case of Parliament - or the governors in the states should appoint someone on their behalf to oversee the oath-taking of the new members.

So, the pro-tem Speaker presides over the initial sittings of a newly constituted Assembly and holds charge till the Speaker is elected, which can take sometime.

According to former Lok Sabha secretary-general P.D.T. Achary, the pro-tem Speaker has all the powers of a Speaker.

Asked whether there were any rules on who could be appointed a pro-tem Speaker, Achary said there were none.

He added, however, that convention suggested that senior-most member of the House be selected for the role.

"That is what has so far been followed in the Lok Sabha, and in most of the Assemblies. But that is just a convention, so there is no way of enforcing it," Achary said.

Among the prominent pro-tem Speakers that the Lok Sabha has had were G.V. Mavalankar - who became the first Speaker - Jagjivan Ram, N.G. Ranga, Indrajit Gupta, Somnath Chatterjee, and most recently Congress member Kamal Nath.