The British constitution has more nooks and crannies than my great-grandmother’s loft, and Parliament has been rummaging around in one of the more obscure ones this week: the royal succession. Two things we all agree – the bypassing of girls in favour of younger boys and the stipulation that neither the monarch nor an heir to the throne can marry a Catholic (or, in the deliberately offensive language of the Act of Settlement, a “papist”) are anachronisms we can dispense with.

But the constitution is a bit like a coarsely woven jumper. Pull one yarn and the whole thing could unravel. So it’s a bit depressing that in the debate it was abundantly clear that the ministers had not really thought through a third element they have put in the Bill, replacing the Royal Marriages Act 1772. This Act was certainly a bad law, brought in at the insistence of George III, who was furious that two of his brothers had married inappropriately. Thenceforth anyone in line to the throne had to get his permission to marry. It didn’t work. Within a decade, George’s son, the Prince of Wales, married a Catholic, Maria Fitzherbert, and since he had not gained royal assent, the marriage was automatically null and void.

The idea that a head of state can decide whom people can marry is a tawdry feudal leftover, but the problem is that the Government has decided to retain a bizarre provision that the next six people in line to the throne will still have to get the monarch’s permission to marry, which can be refused. That’s weird enough. But in addition it’s changed the old Act, which said that if you didn’t get royal consent your marriage was null and void, with the provision that if you don’t get consent you lose your place in the succession. If that had been the case in the 18th century, George III’s refusal to consent to his son’s marriage would have prevented him from becoming George IV.

This runs completely against our history. From the earliest times, Parliament, not the monarch, has decided the succession, as when Edward II and Richard II were forced to relinquish the crown, when Henry VIII died, when James II fled the country and when the end of the Stuart line was imminent. Even when Edward VIII abdicated, Parliament had to pass a new law the next day to allow him to do so and settle his brother on the throne.

Constitutional law has to expect the unexpected, but this ill-thought through Bill will leave the succession to the caprice of the monarch’s preference for in-laws, as a future monarch could deliberately bar a child or a sibling from inheriting merely by refusing consent to marry – and then the European Court of Human Rights would intervene.

Gerrymandering shouldn’t add up

The whip for next Tuesday doesn’t sound very exciting: “Consideration of Lords Amendments to the Electoral Registration Bill”. But the Commons will be very full and the whips will be circling the corridors like angry flies, because beneath the parliamentary lingo lurks an amendment that would delay the Government’s new gerrymandered constituencies until after the next election.

Consider the arithmetic. There are now 303 Tory MPs. The combined Labour and Lib Dem number is 302. Excluding the Speaker and his deputies, there are 27 other MPs in eight parties, and three independents. One missed flight, one angry encounter, could make all the difference to how the next election is to be fought.

My confession to Glenda Jackson

Glenda Jackson has told her local party that she won’t be standing again in 2015. I wrote a biography of Glenda in 1997, but one of the stories I didn’t include happened when I was working for the Labour Party as Frank Dobson’s agent in the next-door seat in 1991. Glenda was hoping to take the seat off the new Tory candidate, Oliver Letwin, and Frank’s daughter Sally (who was working for Glenda) and I were keen to get as many Hampstead and Highgate party members to help with the campaign as possible. So we suggested to Glenda that she might send them all a Christmas card signed by her.

She wasn’t keen at first, but agreed instead to write personal notes to all 2,000 members. It took her the best part of a week, and when she had finished we stamped them and left them overnight in boxes in the office. Unfortunately, that night a pipe in the upstairs flat burst, and when Sally came in the next day a torrent of water had ruined them all. We never dared tell Glenda, not even when she told us that not a single Hampstead member had thanked her, the rude so-and-sos.

Fox is out of his box

In the last 1975 referendum, Harold Wilson refused to tell even his staff how he was voting. On the day, his senior policy adviser, Bernard Donoghue, finally got an answer. He had voted yes. Why? “Because I don’t want that lot [Tony Benn and Enoch Powell] running Britain for the next 20 years.” I thought of Wilson as the Tories cheered Cameron on Wednesday. Like the prisoners in Beethoven’s opera Fidelio, they looked shocked to have lost their shackles, but Bill Cash, Peter Bone and Sir Gerald Howarth – these are the people now pulling the strings of the Tory party.

And Liam Fox. Since he resigned in November 2011, he has asked just 10 questions and made two short speeches. But there he was on Monday, beaming ear to ear, obviously thinking he’s in with a shout of a return to the Cabinet. Moments later, up popped Andrew Mitchell, speaking for the first time since cycling into the distance, and positively shining with the ring of self-vindication. On Wednesday, Fox was letting everyone overhear him as he gleefully told an entourage of young Tory acolytes that Cameron had just won the next election. People, beware