The NSW Liberal government says that the buyback scheme, which was expected to expire yesterday, will be extended for a further three months.

Energy Minister Anthony Roberts said there were a number of titleholders who are still interested in the $212,000 cash offer per licence.

The minister said the scheme extension represents a short window for licence holders to take part in the buy-back, but he warned it won't last forever.

"We're making it making it quite clear to licence holders that they have an opportunity to come to us and be part of this buy-back option before we start to move forward as part of the (NSW) Gas Plan as part of our priorities there, it's a very structured approach where they will be subject to of course use it or lose it provisions," Roberts said in a statement.

He did not clarify how leaseholders can use their leases when they have been effectively prohibited from operations for the past few years.

The government claims its NSW Gas Plan has so far reduced the footprint of CSG across the state from more than 60% to 11%.

The decision to extend the scheme comes a day after Greens NSW CSG spokesperson Jeremy Buckingham called on Nationals member for Lismore, Thomas George, to resign after breaking his promise to buy back PEL 445.

"Thomas George has broken the trust of the people of Lismore and the North Coast by failing to keep his pre-election promise to buy back the North Coast coal seam gas licences and should resign immediately," Buckingham said.

"At the time the promise to buy-back the licence was made, I said that it was simply Thomas George trying to con voters, one week out from an election, into believing he had a significant response to the widespread opposition to CSG in the region and sadly today this has been proved correct.

"This broken promise follows the shocking revelation that it was Thomas George who actually shut down debate on a proposal at the National Party conference to ban coal seam gas in the Northern Rivers," Buckingham said.

George promised that the re-elected Baird government would buy back PEL 445 and would not allow a transfer of the licence to AJ Lucas, which has agreed to buy the licence.

George says he will not resign, and has demanded that PEL 445 be purchased or cancelled.

However, the government cannot force licence owners to sell.

The government has purchased or cancelled 12 PELs across the state including two in the Northern Rivers, PEL 478 and PEL 479, however PEL 445 is a major sticking point given it takes in the areas from which Metgasco claims its protestors game from.

The former owner of PEL 445, Dart Energy, announced earlier this year that it was intending to sell to AJ Lucas, but the government has said it will use its powers to block transfer of the title.

Drilling contractor AJ Lucas bucked a trend to flee NSW in February when it agreed to acquire three CSG licences in the state for $2.5 million, at a time when government policies are effectively telling everyone else to hit the road.

AJ Lucas, no stranger to petroleum exploration or controversy ¬- it upset locals in the United Kingdom with its shale drilling in the Bowland Basin -- announced its intention to secure PELs 445, 456 and 458 in the Clarence-Morton, Gunnedah and Sydney basins respectively from a company associated with director Andrew Purcell.

The UK-born Purcell knows the assets and areas well, having worked in the state with CSG pioneer Sydney Gas Company a decade ago, before helping to put the tenement package together during his time at Arrow Energy and Dart.

Purcell acquired the leases through his company, Lawndale, from iGas, the UK-based company that took over Dart last year, and which had decided that it had better opportunities in Dart's UK portfolio than butting heads with NSW governments on both sides of the fence.

The three blocks cover about 13,000 square kilometres of the state.

Santos is a partner in and the operator of PEL 456 in the Gunnedah Basin, where it has earned 15% and is moving to 50%.

AJL holds 40% of that block and 80% in the other two blocks where it will be the operator.

Substantial exploration work has previously been conducted on PEL and AJ Lucas is confident of the presence of hydrocarbons, with past drilling showing the Walloon Coal Measures contain good to excellent gas composition and are gas saturated.

Arrow completed initial work on the licence before selling out to Dart in 2013 for $200,000.

It is believed that the Walloon Coal Measures contains a significant volume of gas-in-place within the area, with potential secondary targets have been identified in the sandstones of the Bundamba Group and the deeper Ipswich Coal Measures.

PEL 445 is a large permit on the border between NSW and Queensland that is surrounds Metgasco's Casino project where there were significant reserves booked in 2013 of 2500 petajoules (3P).

AJL has already paid a $500,000 deposit for the purchase of the portfolio which is only refundable in the event that the transaction does not complete because of any failure or default by Lawndale.

No new CSG licences have been issued since 2011.

More than $2.5 million has been spent buying back licences, mostly in marginal areas with licence holders offered $200,000 per block when most of them paid only $1000 each for them.