Rover 75 won't start

maybe its the fuel pump

Could be so many things. Start with basics;
Is fuel reaching the plugs?- check if they are wet after cranking.
Is there a spark at plugs?
Check master fuse if there is one
As mentioned on above post re fuel pump-check fuse.

First is the engine turning over but not firing,if so then ignition,compression ,timmong ,issue,if not turning over then starter system issue.

Lift the rear seat and remove the round,black plastic inspection cover above the tank, the pump is now visible, get someone to turn on the ignition while you listen to the pump. It should buzz until fuel pressure is built up

That car does suffer from fuel pump / filter problems .

Checked timing belt ?