Lizzie, get a garage to check it out but I had exactly the same problem in an 06 1.2, noise just happened in cold weather initially (extra strain on the starter) but when it did the same in warmer conditions I replaced the starter motor, they're not too expensive, around £70 or so, plus fitting. No point putting it off as one day your car will simply not start and it could end up costing you more money. Last thing you want is to be stranded somewhere, especially when you know there is a problem that can be easily fixed. Hope that helps.