The Arena and Convention Centre Liverpool has added the Liberal Democrats' spring conference next year to its long list of pre-launch bookings.
The £146m complex, designed by Wilkinson Eyre and currently being built by Bovis Lend Lease, will host 1,500 party delegates between March 7 and 9.
Emma Harris, Liberal Democrat conference coordinator, said: "We chose ACC Liverpool because it is an incredibly impressive facility but also because it is so 'green'."
The building was designed with 'grey water' recycling systems, its own wind farm and carbon emission-reducing materials and energy sources. Practical completion is due at the end of the year and the European Capital of Culture launch party will take place there in January. Nearly 100 events have already been booked to take place at the centre in the next three years.
The visit of the UK's third political party will be seen as a boon for Cllr Warren Bradley, the leader of Liverpool's Liberal Democrat-ruled city council.
Bradley said: "The conference is a key calendar event for the party in which some of our most significant policies are debated and determined.
"Political party conferences are fantastic for a city in terms of raising its profile and hopefully this will be the first of many more to come."
ACC Liverpool will comprise a 1,350-capacity convention centre and adjoining 10,600-seat arena.
Harris said if the event went well the party would seriously consider holding its bigger autumn conference in Liverpool.
The arena, part of the wider Kings Waterfront development, was funded and supervised by a partnership of Liverpool Vision, national regeneration agency English Partnerships, North West Development Agency, the European Objective One Programme and Liverpool City Council.