Theresa May has insisted the Government has a "strong" case to persuade Supreme Court judges to overturn the legal ruling forcing her to gain approval from Parliament to launch EU withdrawal talks.
The Prime Minister also made clear she was not ready to back down on new immigration controls in any parliamentary Brexit battle as she landed in India for trade talks.
And she gave short shrift to suggestions that MPs might tie her hands by requiring her to make continued single market membership her priority during withdrawal talks under Article 50 of the European treaties.
It comes after Labour's deputy leader Tom Watson was forced to insist the party would not try to hold up the process after Jeremy Corbyn appeared to suggest he would block the move if the PM did not guarantee access to single market.
But Mrs May said MPs and peers considering amendments to this effect should remember that "the people spoke on June 23" and it is the Government's job to deliver on their wishes.
The PM brushed aside speculation that she might seek an early election in the hope of securing a Commons majority which would allow her to negotiate on her own terms.
She told reporters: "I've consistently said that I believe the general election should be in 2020."
EU leaders including Germany's Angela Merkel have repeatedly said that the single market - which MPs including former deputy prime minister Nick Clegg see as vital to minimise the damage of Brexit to the UK economy - will be dependent on freedom of movement for EU nationals.
But Mrs May said that MPs and peers should recognise that voters gave a "very clear message" in the EU referendum on June 23 that they wanted tighter controls on immigration.
"I think the people spoke on June 23, I think an important aspect that underpinned people's approach to that vote was a concern that they had about control of movement of people from the EU into the UK," she said.
"I think it's important for the UK Government to deliver on that and I think that MPs and peers should recognise the fact that it was a parliamentary decision to give the choice as to whether or not we stayed in the EU to the people through a referendum vote and we saw the result of that.
"It's now our job to get on and deliver it."
Ministers are reportedly considering plans to present a resolution on triggering Article 50 to Parliament instead of a full Bill, in an effort to fast-track parliamentary approval if the Supreme Court ruling goes against the Government.
Mrs May took a bullish stance on the prospects of overturning the High Court ruling when the Government's appeal comes in early December.
"In terms of the legal situation, we've had two court cases in the UK," she said.
"They've come out with different decisions - the Northern Irish court found in favour of the Government, the High Court found against government.
"We think we have strong legal arguments and we will be taking those arguments to the Supreme Court."