Andy Burnham has plead for Prime Minister Boris Johnson not to scrap plans for the HS2 High Speed rail link to the North.
This comes as supporters of the link between North and South have become increasingly concerned that Johnson may opt to scrap plans to lay tracks up to the North and instead end the line at Birmingham.
Their concerns are bolstered after a leaked report has suggested that the rail link to Manchester should be placed on hold.
A recent inquiry has suggested that the link go ahead to unite the Northern and Southern cities of the UK but that the phase from Birmingham to Mancheser and Leeds be put on hold to reassess the HS2 impact on regional growth.
The future of the project has been previously described as 'Hanging in the balance' with some top aides sceptical of the project.
Burnham has described the leak as 'Worrying', adding that the London and the South gets what it wants and its all about penny pinching in the North.
“Johnson must get HS2 built, in full. Modern railways such as HS2 and Northern Powerhouse Rail are the single biggest means to transform jobs and opportunities for people in the Midlands and the north.
“The possibilities are dramatic.
"Slash the time it takes to get between towns and cities and you transform the way people live, work and do business, creating a powerhouse of jobs and opportunities from Birmingham to Nottingham, from Manchester to Leeds and dozens of places in between.”
He went on to say:
"I would say this to the Prime Minister and the Government today: This is your first big test of your commitment to the North of England and we're watching very closely.
"In my mind there's no justification at all for doing one thing between London and Birmingham, and doing something different in the North.
"If you're going to do it, do it properly. Don't do it by halves."
It is expected that the PM will decide on the next steps for the HS2 project in the coming weeks.
So far over £8bn has been spent on the project with the final cost looking at possibly coming in a £106bn or higher if savings are not made.