A group of Otago regional and Dunedin city councillors will boycott a briefing by Austrian gas giant OMV, as the Dunedin City Council calls on the Government to take action.

Earlier this month, the company unveiled one of the most ambitious gas and oil drilling programmes proposed in New Zealand.

It could include three exploration and seven follow-up appraisal wells off Otago's coast in the Great South Basin, within a 100km-150km arc southeast of Dunedin.

The company is holding a briefing on Monday to explain its plans, and councillors from both councils, among others, have been invited.

Regional councillors Michael Deaker, Bryan Scott and Michael Laws said they would not be attending, citing their opposition, and neither will Dunedin city councillor Aaron Hawkins.

His colleague, Cr Damien Newell, was also undecided, but ''if I go, it will be in protest''.

''The science is in - there's nothing they can tell us.''

The councillors' intentions were clarified days after Dunedin Mayor Dave Cull, encouraged by city councillor Christine Garey, wrote to Prime Minister Jacinda Ardern to reiterate the DCC's opposition to offshore drilling.

The DCC had voted to call for a moratorium on deep-sea oil and gas activities in New Zealand waters in 2015, and current councillors voted 9-4, with one abstention, to reiterate that stance in 2016.

Mr Cull's letter to Ms Ardern, on April 15 this year, reiterated the council was ''strongly opposed'' to offshore drilling, following news of OMV's latest plans.

Mr Cull said yesterday he was yet to receive a response, but supported councillors whether they attended OMV's briefing or not.

Cr Deaker said he wanted to do ''nothing to support or encourage any fossil fuel industry, in Otago or anywhere''.

''I want a wonderful future for our grandchildren and they won't have that unless climate change is stopped.''

Cr Scott felt similarly and preferred to ''establish plans for the future, not the past''.

Cr Laws would also not attend.

''But then I never make 450km round trips to suit the interests of public relations promoters when they could just email their propaganda like most paid lobbyists do.''

Cr Ella Lawton said she would be going, to be informed, but was ''adamantly against'' the plans.

Cr Sam Neill would attend as well, but because fossil fuels would ''be necessary for society for a long time yet''.

Both Cr Andrew Noone and chairman Stephen Woodhead have said they cannot attend, but would have, to better understand OMV's plans.

Other regional councillors could not be contacted.

Among Dunedin city councillors, Cr Hawkins said he saw ''little value'' in the briefing, as there was ''nothing they could say to convince me that the environmental and economic aspirations of our community are well served by more deep-sea drilling''.

Cr Newell was ''absolutely philosophically opposed to the offshore drilling'', which was just ''wilful and wanton damage for our environment and our planet''.

''It's just madness.''

Crs Garey and Jim O'Malley would attend, despite their opposition to drilling, to hear from the company, ask questions and express their concerns and those of the community.

''If I don't like the answer, I'm going to leave immediately,'' Cr O'Malley said.

Mr Cull would not be going, as he would be in China representing Local Government New Zealand, but Crs Doug Hall, Mike Lord, Andrew Whiley and Lee Vandervis - who all supported OMV's plans - would be at the briefing.

Cr Hall said councillors - and the country - needed to consider where it would get its energy from, if not oil and gas.

Cr Lord said he would go ''simply because I was invited'', but was ''very supportive of things that are going to benefit our economy''.

Cr Whiley said he would be ''disappointed'' if councillors boycotted the briefing.

Other city councillors could not be contacted.