Strathclyde says Scottish secretary Ian Lang has ignored the needs of the west of Scotland. Mr Lang announced only one extra ward in the region, in North Lanarkshire.
Des McNulty, chairman of the region's reorganisation sub committee, said the average councillor in the unitary Glasgow council would have to represent nearly 6,000 voters.
Strathclyde will take legal advice on whether it can challenge Mr Lang's method of consultation, The Herald reports.
Borders RC Chief Executive Kenneth Clark warned that the disparity in numbers of members between the new councils 'must affect the credibility of the whole process,' The Scotsman reports (p4).