The prize for opportunistic question of the week at prime minister’s questions on Wednesday went to Iain Mackenzie, the Labour member for Inverclyde.  Inspired by those dramatic photographs of the cruise ship Concordia, diagonally-posed in tranquil waters off the Tuscan coast, Mr Mackenzie rose to challenge the prime minister on the threat of a similar fate awaiting luxury liners heading for Greenock Harbour in his constituency.  This is because apparently someone has sacked all Greenock’s coastguards.

It seems unlikely, in the system of devolved government under which we live, that the prime minister commands much authority over the employment of coastguards on the River Clyde. The point of the question was presumably to demonstrate the unintended consequences of Mr Cameron’s cuts.  Or was Mr Mackenzie just trying to get his face – a tall and tapering construction, not unlike an inverted lighthouse – into the local papers before the Concordia story, unlike the stricken vessel herself, sinks beneath the waves?  Either way, it felt like an improbable premise for a scandal. Is Greenock really a hot destination on that many luxury cruise itineraries?  Nor can there be too much danger of the captain sailing too close to the shore – allegedly the cause of the Concordia’s downfall – for fear of subtracting from the view of Dumbarton on the other side.

Ed Miliband surprised us less with his originality by leading on the subject of unemployment – the obvious topic on a day when the number out of work rose to its highest total for 18 years.  Like all opposition leaders, Miliband over-prepares for PMQs. He has taken particularly to heart the advice given to courtroom lawyers only to ask questions to which you already know the answer.

“Does he think the unemployment situation will get any worse”, Miliband asked Cameron, a pointless piece of artifice, since he knows full well that the Office of Budget Responsibility, the Government’s official bean-counters, say that yes it will. The prime minister answered  by praising his Government’s wise and generous move to set up the OBR in the first place. When these objective and independent folk say we are going to hell in a handcart we know they speak the truth, and are not just trying to sell us a cruise to Glasgow to take our minds off it. What comfort this is supposed to bring to the long-term unemployed is never revealed.

It was all very reminiscent of the 1980s, when government and opposition bickered incessantly about the unemployment figures and whether or not they had been artfully rearranged. It was Miliband who unwisely invoked this comparison. This, after all, was an era when Labour got battered at elections more thoroughly than a North Sea cod. Moreover, the idea that Mr Miliband is Michael Foot with more scrupulous hair and better suits is one that cannot quite be dispelled, and the Labour leader shouldn’t encourage us to think that way.

At heart, however, this is a question of psychology. For Labour the 1980s were an era of betrayal, anger and injustice. In that way there was something real and noble about them, embodying everything the party exists to fight against. For the Tories meanwhile those same years were a golden time of glut and gaiety, when Thatcher was Thatcher not Meryl Streep, and the Liberals had the capacity to annoy no one more important than the Social Democrats.

Andrew Rosindell, the bellicose Tory who sits for Romford, was also in the 1980s spirit. At his last run-out at PMQs, Mr Rosindell had advised the prime minister to stick it to the Europeans at the Brussels summit. Whether Mr Cameron was inspired by Rosindell’s bulldog spirit to veto the European treaty we shall never know, but today the Essex exocet was on Argentina’s case. He  invoked the “30-year war against Argentina” (by which he meant it happened 30 years ago; it isn’t still going on, except perhaps in Romford) to exhort Mr Cameron not to accept any nonsense from Buenos Aires with its new outbreak of low-level aggression against the Falklands.

The prime minister replied accusing the Argentinians of behaving like colonialists and revealing that the National Security Council had devoted much discussion yesterday to the subject. Really? What did they decide? Our ability to send a task force these days is  constrained by the fact that the French need the aircraft carrier back on Tuesdays and Saturdays. Perhaps we will send the new Royal Yacht that Michael Gove wants to build, always supposing that he can find the private companies to pay for it.  Anyway, with our luck, it will capsize on its maiden voyage and end up floating outside Greenock harbour, with nothing showing except the B&Q logos on its hull.