The two proposed sites for a new incinerator have attracted opposition from local groups concerned about the impact on the environment.
Cardiff Against the Incinerator and Stop Newport Incinerator say that a better solution to domestic waste would be to increase recycling targets.
The two bidders, Veolia and Viridor, say that the plans represent a major investment and electricity generated by the incinerator will help power local homes and businesses.
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Swansea relieved the pressure on under-fire manager Bob Bradley with an emphatic 3-0 home victory over fellow strugglers Sunderland.
Sol Bamba was sent off after losing his cool but Cardiff hung on to claim a deserved 1-1 draw at Ipswich.
Today's rain will soon clear south-eastwards to leave a largely dry night with some long clear spells.