The easiest way to reach the Riviera dei Fiori is to fly into Nice, which is 35 minutes from the Italian border.
EasyJet flies to Nice from Belfast, Bristol, Liverpool, London Gatwick, London Luton, London Stansted, Newcasle Bruxelles, Berlin, Dortmund, Paris, Geneve and Basel.
Ryanair flies to Nice from Dublin and to Toulon (1h 30 from Itay) from London Stansted.
The other way is fly to Genoa from London Stansted with Ryanair.
Of course, you can use the traditional Airlines as British Airways, Alitalia, Air France from London City to Nice! , BMI, Aerlingus, etc