If you want a cheap flight from Izmir to London, you've got one airlines to choose from.
Make sure you use the search options above to search for flights to other airports in London, not just London Gatwick. The more options you look at, the better your chance of finding a cheap deal. Just so you know, the flight typically takes 7 hrs 25 mins.
There are about ten flights to or via London every week, so you have plenty of options. Keep your eye out for flights
If you're planning on going to London during this time, you could take a look at other airport options. Or you could try to get a last-minute bargain.