There were moments in Vince Cable's speech to the Lib Dem conference where you had to pause to remind yourself that he is a serving member of the government, rather than an opposition politician. While Nick Clegg and Danny Alexander are focused on ensuring that the Lib Dems receive their share of the credit for the economic recovery, Cable cast himself as a Cassandra warning of a new and dangerous housing boom.
In the most striking passage of his speech, he declared that "there are already amber lights flashing to warn us of history repeating itself" and derided those (George Osborne) who would settle for "a short-term spurt of growth fuelled by old-fashioned property boom and bankers rediscovering their mojo". After David Cameron rather mildly remarked, "It's not right to cast Vince as a perpetual Jeremiah. He can brighten up from time to time", Cable pulled no punches in response, quipping that "David Cameron has called me a Jeremiah, but you’ll recall from your reading of the Old Testament that Jeremiah was right." He added: "He [Jeremiah] warned that Jerusalem would be overrun by the armies of Nebuchadnezzar. In my own Book of Lamentations I described how Gordon Brown’s New Jerusalem was overrun by an army of estate agents, property speculators and bankers.
"The problem we have now is that the invaders are coming back. They have a bridgehead in London and the south east of England. They must be stopped. Instead we need sustainable growth."
Cable has never been a stirring platform orator and the response from delegates was more muted than in previous years but the speech was the most significant he has delivered since becoming Business Secretary. More than at any other point, he has gone exceeding the normal limits of collective responsibility.
While the speech opened with a recollection of the "unhealthy tribalism" and "Tammany Hall culture" that led him to resign from Labour in the 1970s (which he suggested had been reborn in Falkirk and other "Labour fiefdoms"), it was otherwise dominated by excoriating attacks on the Tories. He declared that "the nasty party" was back, with "dog whistle politics, orchestrated by an Australian Rottweiler. Hostility towards organised labour, people on benefits and immigrant minorities." He rebuked his "cabinet colleagues" for "careless talk" about Britain leaving the EU and declared: "Let’s remember that we voted to join the present Coalition. We did not vote to join a coalition with UKIP."
Elsewhere, in a rebuke to those on the right of the Lib Dems, such as Jeremy Browne and David Laws, seeking to push the party in a more free market direction, he warned that it was not enough to be "a nicer version of the Tories", again signalling his instinctive preference for Labour.
Ahead of 2015, the balancing act required of the Lib Dems is to differentiate themselves from the Tories without discrediting the government they have served in for more than three years. After Cable's unreserved attacks on the coalition's economic policies, Clegg will feel that the Business Secretary has failed in that task.