First Minister Nicola Sturgeon has predicted that another independence referendum will take place in Scotland.
But she said it was reasonable for her to wait for clarity on Brexit before setting out a firm position.
Labour's shadow Scottish secretary Lesley Laird has, meanwhile, blamed the prime minister for the uncertainty over the UK and the EU.
Conservative MP Andrew Bowie said the last thing voters want is the general election Labour would like to see.
In an interview for the Andrew Marr Show on BBC One, Ms Sturgeon said: "Another Scottish independence referendum is going to happen.
"Nothing in this life is absolutely certain but I think it's as inevitable as its possible to be.
"Before I set forward a path for Scotland I think it's reasonable for me to know what the starting point of that journey is going to be and the context in which we are going to be embarking on it.
"We need to know - and hopefully we will know this over the next few days and over the next three weeks.
"Is the UK leaving the EU? Is it leaving with a deal? Is it leaving with no deal or is it not leaving at all, perhaps looking at another referendum?"
Ms Sturgeon joined a crowd which has been estimated at over one million people on a march in London to demand a second Brexit referendum.
The first minister said the handling of the Brexit process by the UK government had strengthened the case for Scottish independence.
She added: "The experience of the last, almost three years now: Scotland's vote ignored, the voice of the Scottish parliament ignored, all of the consequences that flow from Brexit completely outwith our control.
"That really does make the case for independence very very powerfully."
Speaking to the Sunday Politics Scotland programme, Labour's Lesley Laird said the fact that there was so little certainty over the way ahead on Brexit was down to Theresa May.
"The reason we haven't got to a position in parliament of being able to formulate a clear view," she said, "is because of the way that the prime minister has handled this whole negotiation.
"She hasn't dealt with parliament, she hasn't given parliament the opportunity to have these discussions around the indicative votes."
But Labour's idea of putting the issue to voters in a general election was strongly criticised by Andrew Bowie, who is a parliamentary private secretary to the prime minister.
Speaking on the same programme, he said: "The vast majority of people in this country, the last thing they want - contrary to the Labour Party - is another general election.
"I'm not in a position, I don't think anybody here is in a position to make a prediction on where we will be this time next week."