Louise Evans from business advisors Grant Thornton says promotion could be worth up to £150m for the club and will have knock-on benefits for the city and Wales.
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Whilst it should be drier than Wednesday, some rain is still expected.
It will stay largely cloudy tonight and there will be some further rain around, with central parts perhaps staying driest.
ITV Wales understands the reason for the inquiry call stems from concerns raised at the end of 2016 over a former healthcare support worker.