Deputy Liberal leader Sussan Ley says it’s important for a woman to be the party’s candidate at the upcoming by-election in Melbourne following Alan Tudge’s decision to quit.

Mr Tudge announced his resignation from federal parliament on Thursday, citing health and family reasons after reporting death threats were made against his teenage daughters.

The announcement has triggered a by-election in Aston, less than a year after the Liberal MP narrowly held on to the outer Melbourne seat at the 2022 poll.

Ms Ley said she had been calling for more women in parliament for “many, many years”.

“We won’t reach parity if we don’t appoint a woman when a man retires,” she told Sky News.

“So I look forward to a woman candidate in Aston. That decision is, of course, one for the Victorian Liberal Party and they will have a great choice to make and I know they will select an outstanding candidate.”

Opposition Leader Peter Dutton has announced new shadow ministerial appointments.

Shadow cabinet shuffle

In a statement on Sunday, Mr Dutton said Victorian Senator Sarah Henderson would move from the communications portfolio to become the coalition’s education spokeswoman.

Former minister David Coleman will return to the frontbench as communications spokesman.

“These new appointments will strengthen the coalition’s representation in critical portfolio areas,” Mr Dutton said.

“I look forward to continuing to work with Senator Henderson and Mr Coleman as they carry out their new roles.”

Mr Dutton thanked Mr Tudge for his service to the coalition since his election in 2010.

“He departs the parliament with the coalition’s best wishes for his future endeavours,” he said.

Mr Dutton has described his party as the underdogs ahead of the by-election, as Mr Tudge held onto his seat by just 2.8 per cent, having suffered a more than seven per cent swing against him at the 2022 election.

Labor Minister Jason Clare said it was “pretty ridiculous” the Liberal party was painting itself as the “underdogs” when no government had won a seat off the opposition in 100 years.

“If the Libs are the underdogs in this election, then they’ve got more problems than a by-election,” he said.

-AAP