The Liberal and National parties in New South Wales are in a bind this weekend, trying to sort out the preselection order for its Senate ticket.

In March, Moree disability campaigner Hollie Hughes won a ballot to take the number one spot on the state's ticket, ahead of Minister Concetta Fierravanti-Wells.

Ms Hughes subsequently ceded her position in favour of Senator Fierravanti-Wells.

But that was before Prime Minister Malcolm Turnbull called a double-dissolution election resulting in all 12 Senate spots in NSW being up for election.

Insiders believe the Coalition will easily win four NSW Senate seats in the July poll, and has a strong chance of taking the fifth spot, but believe the sixth position is unwinnable.

Deciding who will take those winnable positions is now being resolved by the Liberal and National parties.

It is believed the top four spots will be taken by Defence Minister Marise Payne, Cabinet Secretary Arthur Sinodinos, Deputy Nationals Leader Fiona Nash and Minister for International Development and the Pacific, Senator Fierravanti-Wells.

Hollie Hughes ceded her position in favour of Concetta Fierravanti-Wells. ( AAP: Lukas Coch )

The popular Nationals senator John "Wacka" Williams could be given the fifth spot, with Ms Hughes relegated to the sixth position.

Dumping the National Party's Deputy Leader to an unwinnable position would be inconceivable and relegating Senator Williams to the sixth position would risk a community backlash, as for years he has been a vocal critic of the banks and highlighted financial planning scandals.

But some Liberal Party members are deeply unhappy Ms Hughes could be dumped to sixth position, despite winning the top spot just two months ago.

Rumours, allegations and suggestions of dirt files against candidates are now circulating within the Liberal party.

A senior source told 7.30 they were not surprised by this.

It is understood the Liberal Party state executive is trying to resolve the pre-selection order, and will announce a final decision "in due course".