Our opinion poll last week suggested that the political map of Wales is about to change in the Westminster election but the first signs of whether party allegiances really are shifting will come in the local election results throughout the night and tomorrow.
Labour are defending the seats they won in a strong performance by the party five years ago. Probably the biggest indication overnight of whether it's lost as much support as the polls suggest will come in Cardiff. The Conservatives, Liberal Democrats and Plaid Cymru are targeting wards in different parts of the city, making it possible that no one -or even two- parties will have a majority of seats on the council.
The Conservatives top target is the Vale of Glamorgan council but results in Wrexham, Flintshire, Newport and Bridgend will be an indication of how realistic are the Tories' chances of gaining Westminster seats in those places.
Plaid Cymru's council targets in Caerphilly, Rhondda Cynon Taf and Anglesey don't count their votes until tomorrow. That's also true of Gwynedd, the only council where the party currently has an overall majority and Carmarthenshire, where it's in coalition with the independents.
Away from the party contests, independent councillors remain an important part of Welsh local government and their dominance in Powys and Pembrokeshire is set to continue after this election.