Agreement can still be reached on a Brexit deal for Scotland despite time for negotiations rapidly running out, Mike Russell has said.

Scotland's Brexit Minister said he hopes to see more "effective engagement" from the UK Government in the final weeks before the end of March deadline for beginning the EU divorce proceedings, but warned he does not see the process "going well".

He was speaking after experts from the Scottish Government's Standing Council on Europe expressed doubt about a deal being struck on a differentiated settlement for Scotland on European single market membership.

Consideration of the SNP administration's proposals for the Brexit process are to ''intensify'' between now and the triggering of Article 50, following a meeting between the Prime Minister and devolved leaders in Cardiff on Monday.

Former diplomat Dame Mariot Leslie, a member of the council of experts set up to advise Scottish ministers, gave evidence to Holyrood's Europe Committee on the proposals.

She said: "As I understand it, the paper is still under consideration in that Joint Ministerial Commission but with the clock ticking towards the British Government's own timetable of the end of March at the latest for its Article 50 notification, I find it hard to see how a serious and sincere attention could be given to this paper in all its detail in that time, along with all the other things on the agenda, but that's a very personal observation."

Professor Anton Muscatelli, who chairs the standing council, agreed it is a "critical time" for the negotiations.

He said: "There are so many moving parts to these negotiations that unless you can at least have some traction and begin to join some of the moving parts within the UK, then it becomes really much more difficult to do that in the more dynamic environment of the negotiations post Article 50."

Giving evidence to the same committee, Mr Russell said: "Hopefully in the next period we will see more effective engagement and whilst time is running out we still think there is time for an agreement to be reached."

He was asked by SNP MSP Richard Lochhead whether he believes the Scottish Government is being "strung along" by UK ministers.

Mr Russell said: "The engagement is still in place so to that extent I want to see it through in the hope that it will produce the results which were promised.

"There requires to be an agreed position on triggering Article 50 and that's what we're endeavouring to get to, and it's perfectly possible to have a solution based on what is in this proposal, so I am still discussing and negotiating.

"The lot of any human being is to be frustrated from time to time and annoyed from time to time and not entirely pleased... but there are other advantages and at other times you're going well.

"I don't see this process going well but I'm going to stick with it in the hope that we'll get something out of it."