The long-serving Howard Government minister has just avoided a challenge for his seat now that right-wing rival Richard Quinn, a Hunters Hill councillor, has pulled out of the race.

The move follows intense internal Liberal Party lobbying.

It's seen as a victory for the moderates such as Mr Ruddock over the warring right-wing factions trying to dominate party branches of the north-west at state and federal levels.

The bitter tit-for-tat branch-stacking war is being waged by supporters of the Castle Hill Federal MP for Mitchell, Alex Hawke (leader of the so-called soft Right), and his former boss and mentor, David Clarke, the Upper House state MP who leads the hard Christian Right, dubbed the Taliban by rivals.

Mr Ruddock's supporters say it was outrageous that the former immigration minister and attorney-general needed to fight for his seat after almost four decades of service.

They expressed fears that the seat could be won by a right-winger during the current purge.

It's understood Cr Quinn may contest preselection for Bennelong, the seat of former prime minister John Howard until he was ousted by Maxine McKew two years ago.

Meanwhile, The Sydney Morning Herald reported last week that Noel McCoy, a former state president of the Young Liberals and previously on the state executive of the Liberal Party, was understood to have been implicated in the YouTube video scandal and could face suspension from the party.

There's been speculation that Mr McCoy, a David Clarke supporter, would run against Philip Ruddock in Berowra. But suspension would end his political ambitions.

An email trail has already led to the sacking or standing down of Tom Tudehope, an online media adviser to federal Opposition Leader Malcolm Turnbull, and of Charles Perrottet, a David Clarke staffer.

Senior Liberal sources told the Herald that the trail had also implicated Mr McCoy.

All deny involvement and say the emails are doctored.

The party has been embroiled in turmoil over the YouTube video depicting Mr Hawke as Adolf Hitler, berating aides for failing to wipe out the forces of Mr Clarke. A scene from the movie Downfall made its point.

A senior party source confirmed to the Herald that Mr McCoy's alleged involvement was being looked at. Mr McCoy said he could not comment because of Liberal Party rules but he denies any involvement in the production of the video clip and was not aware of being implicated in the investigation.