Click any step to jump to it - the lit step is the one showing below. The convention bends, breaks and reasserts with the PM's authority. Green = strengthened or expanded · Amber = mixed or contested · Red = weakened or reversed.
Timeline tucked away while you test yourself. Close the quiz to bring it back.
What happened. For the EEC referendum, Harold Wilson formally suspended CMR so cabinet ministers, including Tony Benn, could campaign No against the official Yes line.
What it shows. The PM can switch the convention off when the party is split - the first formal suspension, the precedent 2016 followed. Suspended by choice
What happened. In the coalition, the Coalition Agreement listed agreed exceptions (the AV referendum, Lib Dem abstention on tuition fees); Business Secretary Vince Cable openly criticised Conservative policy and stayed in post.
What it shows. CMR diluted by design - with no single-party majority, one voice was impossible. Diluted
What happened. For the EU referendum, David Cameron suspended CMR; six cabinet ministers, including Boris Johnson and Michael Gove, campaigned Leave from inside the cabinet.
What it shows. The second formal suspension - what was exceptional now looks like the standard answer to a Europe split. Suspended by choice
What happened. Governing without a majority, Theresa May saw David Davis and Boris Johnson resign within two days over the Chequers plan in July 2018; cabinet leaks became routine.
What it shows. A weak PM cannot enforce the convention - resignation still happened, but so did open briefing. Breaking down
What happened. After his 2019 majority, Boris Johnson reasserted discipline; Sajid Javid resigned as Chancellor in February 2020 rather than accept No 10 control over his advisers.
What it shows. A strong PM re-imposes one voice - the minister who would not accept central control left. Reasserted
What happened. On 5 July 2022 Sunak and Javid resigned within minutes; over fifty ministers followed in 48 hours and Johnson fell. Then Liz Truss's mini-budget bypassed cabinet entirely and the government fell in 49 days.
What it shows. Two lessons in one year - CMR can still remove a PM by mass resignation, yet can also collapse before a weak PM falls. Collapse, then a weapon
What happened. With a large majority, Keir Starmer's government largely speaks with one voice and breaches have met departure, though cabinet discussions still leak.
What it shows. The convention reappears when the PM is strong enough to enforce it - though leaking persists. Reasserted, with limits
Roll up and down: use the arrows, scroll or swipe inside the box, the up and down keys, or click any step in the arc above.
The pattern across fifty years is not steady decline. It is a convention whose impact rises and falls with the political strength of the Prime Minister.
The two referendum suspensions (1975 and 2016) show the convention bending rather than breaking - both times a PM lifted the rule to stop a Europe split tearing the party apart. The coalition years built the same flexibility into government itself. The Brexit years are the strongest evidence for the "no longer operates" side: May could not stop the briefing, and Truss in 2022 bypassed cabinet entirely.
But the same period supplies the other side. Johnson reasserted discipline after 2019, and Javid's 2020 resignation was the cost of that, not a failure. And the fall of Johnson in July 2022 is CMR working with full force - when the cabinet withdrew support, the PM was gone within two days.
The same events split by side. Build each paragraph around one point from each column, then judge.
The 2022 collapse cuts both ways: it shows the convention breaking down under Truss, yet also working as a weapon that removed Johnson days earlier.
For "Evaluate the view that ministerial responsibility no longer operates effectively", this timeline gives the CMR half of the essay. Pair eras to build PEACE paragraphs that contain both views: the 2016 suspension and May-era leaking argue the convention has lost its force; the Javid 2020 resignation and the July 2022 mass resignations argue it still bites. End each paragraph with an interim judgement.
Keep the dates precise: suspensions 1975 and 2016, Chequers resignations July 2018, Javid February 2020, the Johnson collapse 5 July 2022, Truss's 49 days in autumn 2022.