Lascelles Principles
The Lascelles Principles are a constitutional convention in the United Kingdom beginning in 1950, under which the Sovereign can refuse a request from the Prime Minister to dissolve Parliament if three conditions were met: The convention was in abeyance from 2011 to 2022, when the Sovereign's prerogative power to dissolve Parliament was removed by the Fixed-term Parliaments Act 2011. Following passage of the Dissolution and Calling of Parliament Act 2022, which repealed the Fixed-term Parliaments Act, these principles have been revived. The letter. During public discussion of the King's potential response to the outcome  of the 1950 general election, which returned a very slim Labour Party majority in the House of Commons, the Lascelles Principles were formally stated in a letter by Sir Alan Lascelles, Private Secretary to King George VI, under the pseudonym "Senex" to the Editor of "The Times", published on 2 May 1950: To the Editor of The Times Sir, It is surely indisputable (and common sense) that a Prime Minister may ask—not demand—that his Sovereign will grant him a dissolution of Parliament; and that the Sovereign, if he so chooses, may refuse to grant this request. The problem  of such a choice is entirely personal to the Sovereign, though he is, of course, free to seek informal advice from anybody whom he thinks fit to consult. In so far as this matter can be publicly discussed, it can be properly assumed that no wise Sovereign—that is, one who has at heart the true interest of the country, the constitution, and the Monarchy—would deny a dissolution to his Prime Minister unless he were satisfied that: (1) the existing Parliament was still vital, viable, and capable of doing its job; (2) a General Election would be detrimental to  the national economy; (3) he could rely on finding another Prime Minister who could carry on his Government, for a reasonable period, with a working majority in the House of Commons. When Sir Patrick Duncan refused a dissolution to his Prime Minister in South Africa in 1939, all these conditions were satisfied: when Lord Byng did the same in Canada in 1926, they appeared to be, but in the event the third proved illusory. I am, &c., SENEX. April 29. Thus, the letter asserted the constitutional power of the Sovereign to deny a dissolution, described the conditions for a valid  exercise of that power, and referred to relevant precedents: occasions on which requests for parliamentary dissolution not exhibiting these conditions were refused by governors-general of British Commonwealth nations, acting on behalf of the monarch. Subsequent discussion. Historian Peter Hennessy stated in 1994 that the second of the three conditions had since been "dropped from the canon", being no longer included in internal Cabinet Office guidance. In August 2019, David Herdson of politicalbetting.com suggested the principles could still have relevance if a PM lost a vote of no confidence and then, intending to seek an election rather than allow someone  else to form a government, argued a right to such an election as reason for not resigning and running down the clock.