Nicola Sturgeon has said a Supreme Court ruling that the UK Government is "not legally compelled'' to consult the devolved administrations before formally starting the Brexit process raises "fundamental issues'' for Scotland.
McConnell Pushes Case For No Vote
Scotland should continue to voluntarily share its sovereignty with the rest of the UK in the areas where it is best to work together, according to Lord McConnell.
In his first major speech for the Better Together campaign, the former First Minister said "home rule inside the UK has had good days and bad days, but it works and it will continue to grow and develop".
But former Labour chairman Bob Thomson said only independence will avoid "a re-elected Tory government Scotland voted against".
Lord McConnell will be joined by Advocate General Lord Wallace, who served as his deputy in the last Labour/Liberal Democrat Scottish Government, in a speech to mark the 15th anniversary of the opening of the Scottish Parliament in Edinburgh today.
The Labour peer will say: "I want to set out a positive argument. And be relentlessly positive in doing so.
"I have friends on both sides of this debate and I respect their views.
"But my own view is clear. Home rule for Scotland within the UK is the best and most positive system for the people who live and work here. It gives us the best of both worlds.
"Devolution gives us the autonomy to decide our laws. Our Scottish Parliament has strong powers to make our own decisions and change lives.
"But we voluntarily share our sovereignty with those who live in England, Wales and Northern Ireland in the areas where it's best to work together.
"Together with thousands and thousands of other Scots, Jim and I campaigned for devolution in the 80s and 90s. And then we worked tirelessly to make it work in practice.
"And I will fight between now and the vote in September to make the positive case that Scottish devolution within the UK secures the brightest future for Scotland.
"The facts prove the success of devolution. We still face huge challenges but Scotland is a better place after 15 years of devolution.
"We are healthier, cleaner, more just, more confident, economically stronger and better connected.
"Home rule inside the UK has had good days and bad days, but it works and it will continue to grow and develop.
"The vote in September is not about personalities, or even policies. It is about how we choose to be governed. Democratically, intellectually, and politically I am as convinced as I ever was.
"And I will fight to save home rule inside the UK as the best of both worlds for the nation I love."
But commenting on behalf of Yes Scotland, Mr Thomson said: "Jack McConnell is very welcome to the debate, but of course many others who campaigned long and hard for the Scottish Parliament are in no doubt that the next step must be a Yes vote for independence - not least Canon Kenyon Wright, who chaired the Constitutional Convention.
"A No vote means years of more Westminster austerity, and the danger of a re-elected Tory government Scotland voted against. Only a Yes vote in September guarantees delivery of all the powers Scotland wants and needs, so that we can make our enormous wealth work better for everyone who lives here."
Britain's most senior judges will rule if Theresa May has the power to trigger the formal process for the UK's exit from the European Union.
US President Donald Trump resigned as director of five British companies the day before his inauguration.
The cost of fraud to Scotland soared five-fold to £24.3 million last year, although the number of cases fell, according to new research.
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