Surrey and East County Councils say they want to join forces to save millions of pounds.
The two local authorities are finalising plans to work together to drive harder bargains with suppliers they both use.
They claim collective buying power will cut shared costs by millions of pounds each year.
The partnership will be considered by East Sussex's cabinet on 24th July. Peter Jones, the leader of East Sussex County Council, said it was a ground breaking partnership which would lead to better deals.
The public sector should be seen as a single team co-operating to save money wherever possible while continuing to provide excellent services."
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Highways England thanked people for pointing it out. The A34 sign has now been removed.