After 1970, when the Conservatives were returned to power, serious thought was given to a further programme of closures, but this proved politically impossible. In 1983, under the government of Margaret Thatcher, Sir David Serpell, a civil servant who had worked with Beeching, compiled the Serpell Report which said that a profitable railway could be achieved only by closing much of what remained. The infamous "Option A" in this report was illustrated by a map of a vestigial system with, for example, no railways west of Bristol or Cardiff and none in Scotland apart from the central belt. Serpell was shown to have some serious weaknesses, such as the closure of the Midland Main Line (a busy route for coal to power stations), and the East Coast Main Line between Berwick-upon-Tweed and Edinburgh, part of the key London/Edinburgh link. The report met fierce resistance from many quarters and was quickly abandoned.