It is almost a cranefly. The midge belongs to the genus Trichocera, family Trichoceridae, and is generally known as 'winter cranefly'. One difference with craneflies is the presence of ocelli on the head (you can see some shine between the large eyes).

Although species of the genus are present trhough out the year (in western Europe one summer species and several winter species), the ones active later in the year are more conspicuous while the form swarms in gardens, etc. when hardly any other insects are present. The spider webs around our house are full of them right now.

Paul

http://www.diptera.info