West Midlands Tory mayor Andy Street has said Rishi Sunak would be "cancelling the future" if he "gives up" on the Manchester leg of HS2.
It comes amid speculation that the prime minister is about to announce the axing of the high speed rail line.
Downing Street has insisted "no final decisions have been taken".
But Mr Street made an impassioned plea to the PM to "stay the course" or risk damaging the UK's international reputation "as a place to invest".
At an impromptu press conference, Mr Street warned the PM: "You will be turning your back on an opportunity to level up - a once-in-a-generation opportunity."
Carmen
Expert in language training and educational coordinator at Oxford Institutes. Develops innovative learning paths for English learners of all ages.
