Say 'Non': Sickbed advice on bridge to France
Margaret Thatcher's Welsh secretary warned her against building a bridge between Britain and France based on his "painful" experience of crossings closer to home.
Nicholas Edwards, now Lord Crickhowell, wrote to her in January 1986.
Cabinet Office documents released after 30 years reveal he was "in bed with flu and a temperature" and wanted to put his thoughts on paper.
A bridge was later rejected in favour of the Channel Tunnel.
"I am certain it is right to reject both the Euro Bridge and the Euro Route," wrote the Pembrokeshire MP.
"All my experience, painfully learned with the Severn Bridge and the Cleddau Bridge (which is in my constituency and was the first modern box girder bridge to collapse) warn me against bridge experiments at the frontiers of technology.
"Such structures also seem excessively vulnerable to corrosion and fatigue." He said the proposed schemes had been hastily put together with cost calculations "far too optimistic".
Other papers released by the National Archives show Mrs Thatcher ordered a review of funding in Wales, Northern Ireland and Scotland - amid claims that public spending in Scotland was too high.
The releases also revealed the strength of the former Tory leader's opposition to regeneration of Cardiff docklands and the Cardiff Bay barrage project.
Finally, a gift of moon dust from the United States sparked official concern about when it should go on display in Wales, the archives disclosed.