Can the UK Prime Minister immediately withdraw the country from the EU without backing from parliament?
I am not asking if this is legal, or if it is possible to do without committing political suicide. Let us assume that the next Prime Minister might be so zealous about Brexit that they would be willing to end their career (or if found to have acted illegally, be punished). Could they, on day one of their leadership, take a flight to Brussels and announce that the UK withdraws with immediate effect?
The EU has said on many occasions they will not interfere with the internal politics of Britain on this matter. Does this mean they would have to accept this from the PM whether the PM actually had the power to do it?
Edit: originally specified no deal, which was mentioned as not being possible due to the details of the extension. Ad I understand though it would be possible to accept the negotiated deal at any time. Could this be done without parliamentary approval?