No British Prime Minister has lost a confidence motion since 1979, but I think it's worth noting that a) a PM with a majority can only block a no-confidence vot

No British Prime Minister has lost a confidence motion since 1979, but I think it's worth noting that a) a PM with a majority can only block a no-confidence vote with the support of their party's MPs and b) the threat of a no-confidence motion is frequently sufficient to force a resignation. Callaghan was the last PM to lose a no-confidence vote, but that's not the full story. Major and Brown resigned after losing an election, but Thatcher, Blair and Cameron all resigned as PM. May is expected to resign before the next general election. No US president has resigned since Nixon in 1974, which suggests a marked difference in security of tenure under the different systems - we might not kick our prime minister out of office very often, but they usually leave office of their own volition.