The band, who will play a special gig in Hyde Park on August 12 to mark the end of the London 2012 Olympics, teased fans with the prospect of new material.
Bassist Alex James told Jeremy Clarkson on Top Gear that the track is "like a hymn, a real tear-jerker".
Talking about the group's 'Outstanding Contribution to Music' award at the Brits last month, he added: "It was utterly magnificent to get back together and smash those songs out again."
Blur will be joined by The Specials and New Order for their Hyde Park show. Tickets for the gig are on sale now.
> Blur debut new track 'Under The Westway': Video
Watch the music video for Blur's 'Country House' below: