Loud squealing When driving i hear a loud squealing un till i press the breaks and then the squealling stops. As soon as i take my foot off the break petal the squealing comes back.

Cheap brake pads and mechanics missing out the Anti-Squeal shims or Copper Slip Grease can cause your problem

You could also try power washing the disks or Rotors as our American readers call them

That will remove any brake dust and will either make the noise go away or get worse.

Make sure that you give them time to dry out before you hit the road , or apply the brakes as you drive off to warm them up

Sounds like shims on brakes, or lack of them
thin bits of metal to stop squeel