By John Stevens As the Tory great and the good sipped on Pol Roger champagne at the Spectator magazine’s Christmas drinks party, suddenly everyone started to look at their phones. Rishi Sunak’s long time pal Robert Jenrick had quit as Immigration Minister in a row over legislation aimed at finally getting the Rwanda migrant plan off the ground. “It’s over,” cried one of the guests now convinced this Conservative Government is now in its death throes after 13 years in power. One senior Tory aide joked that Mr Jenrick should be “referred to Prevent”, the Government’s anti-terrorism programme for…