ITV News video report by Scotland Correspondent Peter Smith
"There will be an independence referendum", First Minister Nicola Sturgeon has promised.
Speaking at the SNP Spring Conference Ms Sturgeon said that Scotland would "not be dragged out of Europe by a Tory Government".
The Prime Minister's "refusal to budge an inch" was the reason behind her decision to call a second independence referendum, Ms Sturgeon added.
However, another referendum is not something the Government wants because "they are terrified of the will of the Scottish people", Ms Sturgeon told the packed hall.
Speaking in Aberdeen, Ms Sturgeon said her calls for a second Scottish independence referendum was "music to the ears" of SNP members and nationalists, but the party should "reach out" to those who were undecided and "nervous and anxious, perhaps even resentful".
She added that the Scottish Parliament will be asked next week on a date for the second independence referendum, and that she would negotiate "within reason" of on the timing of such a ballot with Ms May.
To secure a referendum, Ms Sturgeon must secure a Section 30 order which is agreed with the Prime Minister, drafted by both Parliaments and signed off by the Queen.
However, an alternative option would be for Scotland to hold an "advisory referendum", which is not sanctioned by Westminster and not legally binding.
But "change is coming", Ms Sturgeon promised, adding "we can decide on which path we take", that "Scotland's future must be Scotland's choice", and she would "put the people in charge".
The 46-year-old warned Theresa May: "As Article 50 is about to be triggered I would say this to the Prime Minister: stop putting the interests of the right-wing of your party ahead of the interests of the people of our country."
On the status of EU citizens in the UK post-Brexit, Ms Sturgeon warned the Prime Minister: "you cannot lecture others about politics not being a game, while you are using the lives of human beings as pawns."
In contrast to the uncertainty of the status of EU nationals in the UK, an independent Scotland would not "pull up the drawbridge", but would instead "entice the brightest from around Europe", Ms Sturgeon said.
She continued that fears over immigration must not be to the detriment of the economy, and that Scotland needs immigration and would stand against "the demonisation of migrants".
In a more lighthearted tone Ms Sturgeon said that "since the Brexit vote I've had loads of messages from people in other parts of the UK asking if they can move to Scotland".
She continued that following Brexit Scotland "will become a magnet for talent and investment all across the UK... Scotland isn't full up... Come and join us".
Ms Sturgeon also hit out at the "Tory Government dominated by the likes of Boris Johnson and Liam Fox, deluding themselves about rebuilding the Empire and refloating the Royal yacht Britannia.
"It seems they want to go back in time, but it's not just nostalgia for Empire that they're keen on, they clearly long for the days before we had a Scottish Parliament, the days when Tory governments could do what they wanted to Scotland, no matter how often they were rejected by the voters, the days when they could impose the poll tax, destroy Scottish industry and deny all demands for constitutional change.
"Well the Prime Minister should understand this point and understand it well: those days are gone and they are not coming back."
Ms Sturgeon also warned the Prime Minister that if she showed "the same condescension and inflexibility, the same tin ear" to other European nations as she had done to Scotland then "the Brexit process will hit the rocks".
During her speech, the SNP leader slammed the Labour Party as an "embarrassing shambles" and said its current state meant the Conservatives could be in government until 2030.
Ahead of Scottish council elections in May, Ms Sturgeon said: "My message for today is clear, don't let the Tories get their hands on your local services. Vote SNP on May 4", arguing that the SNP focused more on health and community services.
She added that Scotland needed 12,000 new workers with digital skills each year, and said the SNP is to establish a £36 million fund to be spent over three years to help businesses evolve their digital skills.