Now he has published a report about the chances of a Lib-Con pact. Astle argues that policy divisions would prevent Nick Clegg entering into a formal coalition and sitting in Cabinet, but there would be enormous pressure on him to "act responsibly" in a hung parliament and "sustain the Tories in power" if they won more seats."Necessity is the mother of invention," the report notes, "and it may well be that in the high pressured environment of a hung parliament, the underlying forces driving the parties apart are counteracted, at least in part, by other, more immediate factors which conspire to push them together."
But those centrifugal forces should not be underestimated, The CentreForum report goes on to outline some of the key policy differences between the parties on the economy, the environment, as well as on security, home affairs and immigration. Then there are the non-policy issues, including a history of mistrust, the different cultures within the two parties, as well as electoral imperatives. The last point is key - for as long as the electoral success of each party depends on the failure of the other, co-operation will be hard to establish.
But for clues as to what Clegg would do in the event of a hung parliament, the CentreForum’s report is required reading.