The employment threat from the plunging oil price has produced the "the most serious jobs situation Scotland has faced in living memory" with urgent changes to the tax regime required, Holyrood's Energy Minister said.

Fergus Ewing demanded action from the UK Government as Energy Secretary Ed Davey was visiting Aberdeen to talk to leading figures in the North Sea oil and gas sector.

With Chancellor George Osborne due to unveil his final budget before the election in March, Mr Davey suggested "we may well be able to have extra help for the North Sea".

The UK Government minister also said that the drop in oil prices - which have now fallen to below 50 US dollars a barrel - would have left Scotland in a "frankly dire" financial situation if the country had voted for independence last year.

But Mr Ewing said the two governments needed to"put the politics aside" and get a new tax deal implemented for the North Sea "because it will save jobs".

He insisted action was needed before the budget, warning that "unless there is swift action to introduce that tax package, then investment decisions will be made between now and March prematurely to decommission fields which should carry on in production for many years if not decades to come".

Scotland's First Minister Nicola Sturgeon was in Aberdeen yesterday where she announced a new task force to help address the threat to jobs that comes from the drop in oil prices.

Meanwhile workers at oil giant BP are bracing themselves for job losses. The firm announced restructuring plans last month following the fall in oil prices and is expected to give information today on its plans affecting jobs.

Mr Ewing told BBC Radio Scotland's Good Morning Scotland: "Our thoughts are with all the people in the North East of Scotland in particular who face job losses at this time. That is why the First Minister announced yesterday the formation of a task force."

The Scottish Government has also been pressing Westminster to make a series of tax changes to help the industry, including the introduction of an investment allowance, tax credits for exploration and a reversal of the previous hike in the supplementary charge.

These measures combined could boost investment in the North Sea by more than £40 billion and support more than 30,000 jobs, according to Mr Ewing.

He said: "We set out our proposals last week for an investment allowance, exploration tax credit to bring up the woeful level of exploration at present and also a removal of the 12% hike in the supplementary charge on a timed basis.

"The reason that the need for speed is so important, is from my detailed discussions with industry in nearly 60 days spent in Aberdeen as Energy Minister I can tell you that unless there is swift action to introduce that tax package, then investment decisions will be made between now and March prematurely to decommission fields which should carry on in production for many years if not decades to come."

Mr Ewing continued: "It is clear to me that the UK Government has accepted it must act on tax, my question is why wait in respect of the supplementary charge until March?

"The supplementary charge was hiked up by 12% precisely because oil prices were relatively high, now they are shockingly low surely swift action is required.

"If there is a benefit in being in the United Kingdom, and I don't want to re-run this argument, surely the need for swift action by government is paramount and when there is an urgent situation ... I think this is the most serious jobs situation Scotland has faced in living memory."

He refused to say precisely how many jobs could be at risk, but added: "A package of tax measures, if introduced quickly, will avert job losses because it will give confidence and succour back to investors and boardrooms around the world who are looking for a sign that the UK Government has got it."

Drilling for new oil fields in UK waters fell by a fifth last year, while exploration in other North Sea countries remains buoyant, according to a petroleum analyst.

The UK Government must say what fiscal incentives it will provide to encourage exploration in the UK Continental Shelf after drilling fell by 20% from 50 new wells drilled in 2013 to 40 last year, Deloitte Petroleum Services said in its 2014 end-of-year review.

Graham Sadler, managing director of Deloitte's Petroleum Services Group, said there was a need for "further clarity from Government over the fiscal incentives that will be made available to support exploration and appraisal activity"

Mr Davey told BBC Radio Scotland's Good Morning Scotland programme: "I can't prejudge what the Chancellor will announce in the March Budget, but I wouldn't be coming to Scotland today to talk to the industry if we weren't thinking about those issues."

After last September's vote on Scottish independence he said: "One of the reasons why I was keen the United Kingdom stayed together is because we are stronger together; if Scotland was having to face this alone, its financial situation would be, frankly, dire.

"We may well be able to have extra help for the North Sea - we want to work out the best thing to do in the short term and in the long term - but because the UK is stronger together it is able to make those decisions. That's good news for the north east of Scotland, it's good news for the whole of the United Kingdom."

The Liberal Democrat said the UK Government anticipated that the falling oil price could result in "some difficult decisions for many oil and gas companies".

"One of the reasons I'm going to Aberdeen today is to think about the immediate challenge of jobs. Nearly half a million people are employed directly or indirectly in the oil and gas industry not just in Aberdeen and Scotland but across the UK. It is absolutely vital for our economy."

He stressed the UK Government's long-term approach to the sector, saying that "now that the sunshine has gone away and it is raining and it's difficult times for the industry, we've been planning for those times".

Mr Davey added: "We need to look at things like the tax regime and other things we can do to work with the industry. One of the reasons I'm going to Aberdeen is to engage with the industry, to listen to them, and not over-react to short-term changes in the oil price.

"I want to talk to the industry to ensure we are thinking long term."

The GMB trade union, which represents those working offshore in Noth Sea, warned that decisions about the future of the industry should not be made "on the hoof".

GMP representatives, and figures from other unions and the sector, are due to meet in Aberdeen tomorrow.

David Hulse, the union's national officer, said "GMB is asking contractors and clients in the North Sea oil and gas industry to hold off from making fundamental decisions affecting the long-term future of this industry until we have all had a proper chance to assess the current situation and what needs to be done, including action by UK and Scottish Governments.

"We do not want decisions made on the hoof that could have long-term implications. We hope to be clearer after tomorrow's meeting."

Meanwhile, the British Airline Pilots Association (Balpa) said after a special meeting today that firms should resist any pressures to "cut corners" in the wake of falling oil prices, as this would put the safety of pilots and oil workers at risk.

It said there had been five "significant incidents" in the last four years, including two fatal accidents.

Balpa general secretary Jim McAuslan said: "When the industry has its back to the wall there will be a temptation - even unconsciously - to cut back. Our warning to the oil and helicopter companies is to make sure safety isn't compromised."