The Scottish Greens said a single issue general election on independence has to be an option if formal consent for indyref2 is not granted.
Co-leader Patrick Harvie said it would be the only alternative if both Prime Minister Boris Johnson and the Supreme Court block the request.
Opposition parties have criticised the strategy and its timing.
It comes after First Minister Nicola Sturgeon last week proposed holding a referendum on 19 October 2023.
The UK government said it would examine the first minister's proposals, but stressed that its position that "now is not the time" for another referendum had not changed.
It has also said that it is "clear" that the constitution is reserved to Westminster.
A new poll found showed 44% of Scots are opposed to another referendum, with 43% in favour.
The research by Panelbase for the Sunday Times also indicated that 48% would vote for independence, with 47% against, while 5% were undecided.
In 2014 Scotland voted to stick with the UK by 55% to 45%.
https://www.bbc.co.uk/news/uk-scotla...itics-62028031