The benchmark FTSE 100 index was down 48 points, or 0.51%, at 6736.92.
Miner Fresnillo lost early gains and is now down 0.4%. EasyJet, is down 2.21%. Rival International Consolidated Airlines Group is also lower by 1.45%.
European markets suffered more than London, with Germany’s Dax down 1.2% and Paris’s Cac down 1%.
Earlier, Asian markets were also depressed by the Greek debt situation.
On the currency markets, the pound was down 0.21% against the dollar at $1.5528 and was flat against the euro at €1.3820.