FAO Anyone that knows about cars

I have a 2002 Clio that after about 20 minutes of driving will start to 'judder' when pulling off in 1st gear and also a bit more when in 2nd gear. It doesnt seem to be as noticable in higher gears. The problem is worse when going up a hill. Temperature level seems fine.

Anyone any ideas on what it could be? I thought that maybe the spark plugs could be the cause.

I had a car that juddered and lost power, especially going up hills. I changed the plugs and it was fine then