The Liberals are facing the prospect of losing another seat to a "teal" independent after frontbench MP and leading moderate Paul Fletcher announced he would not contest the next federal election.

Mr Fletcher has held the seat of Bradfield in northern Sydney since 2009 and served in cabinet as part of the Turnbull and Morrison governments, holding a series of portfolios including communications, urban infrastructure and the arts.

He suffered a 15 per cent swing against him at the last election, with "teal" independent candidate Nicolette Boele turning the once-safe Liberal electorate into a marginal seat.

She plans to run again at the next election, which is due to be held within months.

Mr Fletcher's departure from parliament marks a further decline of the moderate wing of the Liberal Party, coming just two weeks after fellow moderate Simon Birmingham announced his retirement from politics.

In a statement, the Sydney MP said he would stay in parliament until the election was called.

"Last week, I marked 15 years as Member for Bradfield. Renewal is healthy, for people and institutions, and now is the right time to hand over the baton," he said.

"Once my term ends and I have taken some time for travel and rest, I plan to return to the private sector."

Opposition Leader Peter Dutton paid tribute to Mr Fletcher, describing him as "a man of superb character".

"Paul has been a trusted part of my leadership team, and I am incredibly grateful for his loyalty — not only to me but to all of his Liberal colleagues," he said in a statement.

Fletcher's retirement a surprise to colleagues, but a boost to the 'teals'

Only a week ago, Mr Fletcher launched a major attack on the teals, using a speech to the Sydney Institute to denounce them as a "Green left con job", and gave no signal of his intention to retire from public life.

Mr Dutton praised the speech as "a tour de force in exposing the true colour of the teals and their track record".

Several colleagues expressed surprise at Mr Fletcher's decision to retire, noting he had kept his plans close to his chest.

At the weekend, it became clear Mr Fletcher would face a battle to retain his seat when independent MP Kylea Tink — whose neighbouring seat of North Sydney is being abolished — announced she would not run in Bradfield.

It gives Nicolette Boele, who has already attracted significant community and financial support, a clear run at the seat.

In the forthcoming election, the Liberal Party will be trying to win seats in the suburbs from Labor MPs and in inner city areas from independent teals — named after the blue-green colour to reflect policy concerns traditionally aligned with the Liberal Party (represented by blue) and environmental concerns (green).

The success of teal candidates at the last election saw the ousting of several moderate Liberal MPs, including Trent Zimmerman, Tim Wilson, Dave Sharma and Jason Falinski.

It followed earlier departures from political life by leading moderate figures such as Malcolm Turnbull, Julie Bishop, Christopher Pyne and Marise Payne.

With Senator Birmingham and Mr Fletcher now departing, the conservative wing of the Liberals has overwhelming dominance in the parliamentary party room.

Major frontbench reshuffle looms for Liberals ahead of election

The retirement of the moderate pair also gives Mr Dutton the opportunity for a major reshuffle of his frontbench ahead of the election campaign.

Particularly crucial will be the selection of a new foreign affairs spokesperson to take over from Senator Birmingham, at a time when overseas conflicts are having a significant bearing on the political landscape domestically.

Mr Fletcher has said he will continue to campaign for a Dutton-led coalition to win the next election.

"Two years ago, political commentators wrote off our chances of coming back any time soon: thanks to Peter Dutton's focus and leadership, the next election is now extremely contestable," he said.

Liberal pre-selection for Bradfield is expected to be hotly contested, with Gisele Kapterian — the candidate pre-selected to contest the seat of North Sydney for the Liberals before it was abolished — considered an early front-runner.

In a statement, Ms Boele thanked Mr Fletcher for his service, whilst calling for change at the polling booth.

"For 75 years, one political party has held Bradfield. Now is the opportunity for an independent to make a difference," she said.