The state government has today taken the extraordinary step of officially closing the formal business of parliament, ensuring the Opposition will be blocked from holding its inquiry into the electricity sale.

In a statement released by the Premier's office this morning, Kristina Keneally said the NSW Governor, Marie Bashir, had prorogued the parliament, effective immediately.

Kristina Keneally ... going into campaign mode. Credit:Jon Reid

This means that committees cannot hold hearings before the March election, including the planned upper house inquiry into the government's controversial $5.3 billion sale of the state's electricity assets.

In a bid to stave off expected criticism of its timing, the government's statement highlighted other occasions when parliament was prorouged so early before an election, including on December 7, 1994 before the 1995 election and January 31 before the 2003 election.