Diesel Mondeo 2.0 TDi 2002 - jerks in all gears and driving me CRAZY !!!!

Hi

I have a 2002 diesel Mondeo 2.0 TDi (UK) and when I drive it in any gear it shudders at about 2000 - 2500 revs like there's not enough fuel getting to it - I recently had a full service carried out and then I had the fuel filter changed again and still no joy but it only happens between 2000 and

2500 revs in any gear, I've also noticed that it's vast amounts of "poke" appeared to have dwindled somewhat - it still get's up to speed but takes much longer to get there

Any suggestions would be gratefully received

Thanks Gary