Opposition Leader Tony Abbott has warned his coalition team against hubris ahead of the September 14 election.

With the coalition holding a clear lead over Labor in the polls, Mr Abbott told the first joint partyroom meeting of 2013 that members could be "confident and optimistic but never arrogant" about victory.

Mr Abbott said all Liberal and National members needed to be strong and measured in their criticism of the government, avoid any "personal snideness" and conduct themselves as a "worthy alternative government".

Deputy leader Julie Bishop told the meeting it was possible the government could go to an election earlier than September 14, despite Prime Minister Julia Gillard setting the date last week.

She said it should not be assumed that Ms Gillard would be the Labor leader by the next election, with both Kevin Rudd and Foreign Minister Bob Carr actively positioning themselves.

Shadow treasurer Joe Hockey joked with colleagues about his recent weight loss.

"If I'm prepared to do this to my waist, think what I'm prepared to do about Labor waste," Mr Hockey said.

In a broad outline of the coalition's budget plans, he said medical research and defence spending would not be cut and superannuation tax breaks would remain.

Mr Hockey said Labor's proposed axing of superannuation tax breaks would affect more than just the wealthy, citing a $1 million personal super fund as being modest.

"The Labor Party is coming after your money," he said.

The party room unanimously decided to oppose proposed anti-discrimination law changes, which have yet to be formally drafted or presented to parliament.

Mr Abbott told the party room the coalition had a duty to oppose restrictions on freedom of speech.