Environmental campaigners boarded an oil rig as it was being towed out to sea and staged a climate protest onboard.

Greenpeace activists say they scaled the 27,000-tonne Transocean rig Paul B Loyd Junior,  - thought to be operated by BP - as it attempted to leave Cromarty Firth.

It is said to be a continuation of protests over BP's oil exploration and production plans which comes three weeks after demonstrations when oil company executives met to hold their annual general meeting in Aberdeen.

HeraldScotland:

The protesters are calling for BP to end drilling for new oil wells and say they are prepared to stay on board the rig "for days".

BP said it shared the protesters' concerns about climate change and was working with the rig owner Transocean and the authorities to try to resolve the situation.

At approximately 6.30pm on Sunday, campaigners in a boat pulled up alongside the rig near Inverness, climbed aboard and unveiled a banner declaring a climate emergency.

While occupying a gantry on a leg of the rig below the main deck, the two activists want to stop the drilling rig reaching the Vorlich oil field where it is believed to be trying to extract up to 30 million barrels of oil.

READ MORE: Greenpeace activists scale BP's London headquarters in oil protest 

Greenpeace told supporters: "BP are frequently talking about their efforts to combat climate change, yet this rig is attempting to reach an oil field to access roughly 30 million barrels of oil.

HeraldScotland:

"We can't afford to burn this oil if we're going to avoid the worst impacts of climate change. 

"We're stopping the rig from reaching the oil field. BP can't go on with business as usual."

Jo, a Greenpeace activist from Scotland who is on board the rig, said they said intended to stay on board as long as they can but conceded they would only be able to delay the rig's journey for a few days.

"Warm words flow from BP on their commitment to tackling climate change, yet this rig - and the 30 million barrels it seeks to drill - are a sure a sign that BP are committed to business as usual, fuelling a climate emergency that threatens millions of lives and the future of the living world," she said.

"We can't let that happen - that's why we're here today.

"The Government may be bent on draining the North Sea of every last drop of oil, but this clearly contradicts their climate commitments.

"The perverse idea we must maximise our oil and gas reserves cannot continue.

"That means the Government must seriously reform the Oil & Gas Authority and instead invest heavily in the crucial work of helping oil communities like those in Scotland move from fossil fuels to the industries that will power our low carbon future."

Since BP’s 2018 carbon emissions rose to their highest in six years, the London-based energy firm has been lobbied by activists and an increasing number of shareholders to ensure its operations are in line with goals set by the 2015 Paris climate deal to curb global warming.

It comes after it emerged in April that BP had approved the latest in a series of North Sea developments while seeing profits fall eight per cent in the first quarter amid oil price volatility.

These include plans to develop the Seagull field in the North Sea, which Mr Gilvary described as an advantaged oil project.

Last year BP approved plans to develop the Vorlich find east of Aberdeen and the Alligin field West of Shetland.

Responding to the protest, a spokeswoman for BP said: "In all operations safety is our top priority.

"While we recognise the right for peaceful protest, the actions of this group are irresponsible and may put themselves and others unnecessarily at risk.

"We are working with Transocean - the rig's owner and operator - and the authorities to assess the situation and resolve it peacefully and safely.

"We share the protesters' concerns about the climate. We support the Paris agreement. And we are working every day to advance the world's transition to a low carbon future.

"We're reducing emissions from our own operations - down 1.7 million tonnes last year - improving our products to help our customers reduce their emissions, and creating new low carbon businesses. We are committed to being part of the solution to the climate challenge facing all of us."

Police Scotland said on Sunday night they were aware of an ongoing incident but that the situation was currently within the jurisdiction of the Cromarty Firth's Port Authority.

A spokesman for the Port Authority said he was unable to comment at this stage.

BP plans to double its North Sea production to 200,000 barrels of oil per day by 2020, and add 900,000 of globally by 2021.

But the company has cut greenhouse gas emissions by 2.5 million tonnes since the start of 2016, putting it on its way to hit a target of 3.5m tonnes by 2025.

The approvals reflect a big change in the company’s attitude to the North Sea since selling off a raft of older North Sea assets and shed hundreds of jobs in the area in response to the crude price plunge between 2014 and 2016.

At its annual meeting in Aberdeen, last month, BP backed a resolution put to investors for it to be more transparent about its emissions, link executive pay to reducing emissions from BP’s operations and show how future investments meet Paris goals.

The motion, whose proposers included a group of 58 investors holding 10 percent of its shares, known as Climate Action 100+, passed with 99% shareholders support.

HeraldScotland:

A separate resolution drawn up by activist group Follow This that would require BP to reduce emissions not just from its own activities but also from the fuel and products it sells to customers, is understood to have been opposed by the company and was rejected by 92% of shareholders.

Activists had earlier interrupted the meeting shouting "this is a crime scene" in a protest over ending new oil and gas exploration some carrying yellow mock police cordon tape.  They were led away by security staff.