It will turn over but not catch and it is getting really annoying. Sometimes it starts first time sometimes it just won't. Any ideas what it could be anyone?

Yup..its a renault :-p lol

it sounds like the TDC sensor, sometimes called the crank sensor.

If ur car runs fine once it has started then most likey it is the tdc sensor thats at fault.

Its a cheap part around £20.00. its a common problem with renaults, try german swedish & french car parts web site & u will pick one up cheaply.

If u do not want or feel unable to change it yourself a local garage should be able to replace it quiet cheaply too

best of luck