SCOTLAND could be on the verge of a post-Brexit North Sea boom in decommissioning oil rigs as negotiations open on multi-billion pound contract rule changes.

One of the international trade world's most influential lobbying organisations, the UK Chamber of Shipping, has called for urgent reforms of UK red-tape to free up Scots fleets for the new £50bn industry that will eventually employ 40,000 breaking down the redundant structures.

The group that represents 175 major shipping companies - a third of which are Scottish - including Stena Line, Maersk Line, Calmac Ferries and P&O Ferries has also called for "a simple and straightforward visa regime that enables UK shipping companies to compete in world markets".

Read more: Beyond Brexit - 'Poisonous' Brexit rhetoric could damage Edinburgh International Festival, says director

The news comes as Scottish Rural Economy Secretary Fergus Ewing met industry operators at a summit in Edinburgh that broached maintaining the current increase in cruise ship tourist traffic.

The high-powered chamber makes the beyond Brexit move in its Blueprint for Growth which is due to be released later this month and it also says Westminster must "ensure tourist and business visitors to Britain are welcomed with a simple, quick and effective system for entry into the UK, and that UK citizens returning home are processed quickly at border controls".

However, it said urgent regulatory reforms are needed which include factoring in the British supply chain benefit is a key deciding element when awarding of government contracts such as in the North Sea.

The document obtained by The Herald states: "Bidders should be required to set out the minimum UK supply chain content that they would use as a condition for entering the tendering process."

Read more: Beyond Brexit - 'Poisonous' Brexit rhetoric could damage Edinburgh International Festival, says director

It says: "Decommissioning is a new industry that will involve removal of the large installations from the North Sea.

"Over the next 35 years, the sector could employ 40,000 people and be worth £50bn.

"If the UK becomes the first country to initiate decommissioning work, British companies will be in an excellent position to export their expertise to other nations."

The document continues: "The offshore support vessel sector is essential to the UK’s offshore supply chain.

"British companies that operate these vessels have a leading reputation in the oil and gas and renewable energy sectors."

However "protectionist legislation in other markets – such as the USA and Brazil – limits the opportunities for UK companies to operate overseas".

The UK Chamber does not seek similar protectionism for the UK sector it said but Government "should consider the extent to which HM Treasury will benefit - from greater tax revenues and reduced expenditure on social security in respect of people who are able to join or re-enter employment - when considering bids for work on projects in these sectors".

Read more: Beyond Brexit - 'Poisonous' Brexit rhetoric could damage Edinburgh International Festival, says director

It also pointed to offshore renewables saying: "Under a strong growth scenario, the sector would deliver £7bn gross value added to the UK economy in 2020/2021 and support more than 30,000 full-time jobs.

"However, a firm commitment from the Government on a domestic employment development strategy is missing."

The summit comes as Cruise Scotland announced an estimated 520,000 passengers disembarked at ports across Scotland in 2016, a 14.7 per cent increase on last year in a sector that has almost doubled in size since 2010 when there were around 268,000 passengers.

Mr Ewing said the nature of the industry dictates that business planning must take place up to two years in advance "meaning the uncertainties facing most businesses are accelerated for the cruise industry".

He said: "In particular the on-going uncertainty over the UK Government’s position on EU Freedom of Movement puts the growth of our cruise industry under real threat."