The Scottish Government has demanded to be treated as an "equal partner" by Theresa May in the Brexit negotiations as the Prime Minister called for a "grown up" relationship with the devolved administrations.

The Prime Minister will host the leaders of Scotland, Wales and Northern Ireland on Monday to discuss the Brexit process and her Government's economic plans.

The Joint Ministerial Committee (JMC) will meet for the first time since the European Union referendum and Downing Street said the talks would discuss how the administrations in Westminster, Holyrood, Cardiff Bay and Stormont could work together to secure the best Brexit deal.

Ahead of the talks, the lead Scottish minister involved in the process warned that the Government in Edinburgh was becoming increasingly concerned about the prospect of a "hard Brexit" and called for a new approach from Mrs May.

Michael Russell, the Minister for UK Negotiations on Scotland's Place in Europe, said: "The UK Government needs to understand there is a triple mandate to maintain Scotland's relationship with, and place in, Europe.

"The clearly expressed views of the people of Scotland, the democratically elected Scottish Government and the Scottish Parliament all need to be respected.

"But four months on from the referendum, we have yet to see a proposal from the UK Government on how the views of people in Scotland will be taken into account.

"The Scottish Government is becoming increasingly concerned that the UK is heading for a hard Brexit with all the damage that will bring to the Scottish and UK economies.

"The Prime Minister has set the clock ticking and the UK Government must use the time before triggering Article 50 to engage properly with all the devolved administrations and show that they are willing and able to treat Scotland as an equal partner."

Nicola Sturgeon's administration has drawn up draft legislation for a second referendum on independence, with the First Minister suggesting Scots should have the ability to reconsider the issue in light of the vote for Brexit.

Downing Street has insisted that the Holyrood government has no mandate for a second referendum after independence was rejected in 2014 and the issue could cast a shadow over the talks on Monday.

Mrs May insisted that the UK will "achieve far more together than we ever could do apart" as she called for a mature relationship between the different administrations.

"When I stood upon the steps of Downing Street I made clear the importance of our great Union," she said.

"Far more than mere geography brings us together - and we are much more than the sum of our parts. As we move into this new chapter, we must seize the opportunities ahead, as we will achieve far more together than we could ever do apart.

"I want Monday's meeting to be the start of a new grown up relationship between the devolved administrations and the UK Government - one in which we all work together to forge the future for everyone in the United Kingdom."

Ms Sturgeon, Northern Ireland's First Minister Arlene Foster and Deputy First Minister Martin McGuinness will be at the London talks along with Welsh leader Carwyn Jones.

Mrs May will use the meeting to propose strengthening the JMC, which has not been held since December 2014, making it an annual occurrence hosted by each of the four governments on a revolving basis.

She will invite the leaders of the devolved administrations to take up a key role in building the UK's new industrial strategy in an effort to spread jobs and growth across the country.

Business Secretary Greg Clark will make a presentation on the issue at the meeting.