The House of Commons met at 6.00pm that evening and the Prime Minister spoke firmly, beginning "The time has come when action rather than speech is required." Harold Nicolson, a government MP but a critic of appeasement, thought it was "generally approved" on both sides of the Chamber, although ominously he observed there was no time limit in the message to Berlin. After generally supportive speeches from Arthur Greenwood, the deputy leader of the Labour Party (Labour leader Clement Attlee being absent due to illness), and Sir Archibald Sinclair, the Liberal leader, the House passed 18 emergency and war provision bills which all received the Royal Assent a few minutes before midnight.

Saturday 2 September was a day of high drama. The House of Commons met at 2.45pm with the Chancellor of the Exchequer, Sir John Simon, due to make a statement. However, as he was walking towards the Chamber he received an urgent message not to deliver it, as there had been a new development from Italy. Simon instead told the House that the Prime Minister would make a statement later. Then followed the second reading of several war measures until just after 6.20pm when the Speaker suspended the sitting, expecting an imminent statement from the Prime Minister. Instead, there was a tense wait of around a hundred minutes.

During the afternoon the Cabinet met at 4.30pm, when they heard that the Italian dictator, Benito Mussolini, had proposed a cease-fire and an international conference. However, the cabinet was unwilling to consider this unless German forces were completely withdrawn from Polish territory. According to the diary of Euan Wallace, the Minister of Transport, "we agreed that an announcement must be made in both Houses immediately of the issue of an ultimatum to Germany to expire at midnight tonight".

However, telephone consultations with the French government, who wished first to complete their mobilisation, led to further delay and it was not until 7.44pm that the Prime Minister delivered his statement. Henry Channon, Parliamentary Private Secretary to the junior minister at the Foreign Office, described the Chamber as "crowded and grim" and noted in his diary that "the long wait had irritated everyone", with many MPs passing the time in the bar – "one noticed their flushed faces".

The tone and content of Chamberlain's speech "horrified" Wallace and other ministers as it differed substantially from the Cabinet decision in its vagueness, saying only that the UK was considering with France the issuing of an ultimatum. Harry Crookshank, the junior minister at the Treasury, wrote in his diary that Chamberlain's speech "left the House aghast. It was very badly worded and the obvious inference was vacillation or dirty work." There was widespread shame that German forces had now been attacking Poland for two days, and concern that instead of honouring the guarantee Chamberlain might seek further negotiations with Hitler. The Prime Minister himself told his sister privately a week later that "the House of Commons was out of hand, torn with suspicion, and ready ... to believe the Govt guilty of any cowardice and treachery".

In this febrile atmosphere, as Greenwood rose to reply from the Labour front bench there occurred one of the most famous interjections in parliamentary history: Leo Amery wrote in his diary, "I could not help when Greenwood rose shouting to him to 'Speak for England'." Even though he was a critic of appeasement, for such a senior Conservative – an MP since 1911 and a former cabinet minister – to appeal to the Socialist opposition to save the nation's honour was a striking sign of the unrest on the government benches. Crookshank recorded that "some of our chaps shouted when Greenwood spoke 'speak for England and its honour'", whilst Nicolson noted the Conservative anti-appeaser Bob Boothby "calling out 'You speak for Britain'" and "Greenwood almost staggered in surprise". The Labour deputy leader declared himself "gravely perturbed" and demanded "that there shall be no more devices for dragging out what has been dragged out too long".

Sitting next to Amery were the two Conservatives who had previously resigned from Chamberlain’s Cabinet over appeasement – Anthony Eden, the former Foreign Secretary who resigned in February 1938, and Duff Cooper, the only member of the Cabinet to oppose the Munich agreement. The latter wrote in his diary that after Chamberlain's speech many government MPs sitting in front of them urged Eden to speak, but instead Cooper turned to the person who happened to be sitting on his other side. This was Sir John Wardlaw-Milne, a respected moderate who was normally a staunch supporter of the leadership. In May 1939 he had been elected chairman of the party’s backbench Foreign Affairs Committee by packing the meeting with Chamberlain supporters, but now he "was feeling as strongly as anybody". With an acute sense of political tactics, Cooper "thought it would be much better if he spoke than any of us [critics] did – and I urged him to do so."

Wardlaw-Milne's brief speech reminded the Prime Minister that it was 38 hours "since this war began" and "the whole country is nervous about this continual delay in carrying out our pledges". Coming from such a loyalist source, the speech "carried great weight" and Cooper recorded "I have never felt so moved." The atmosphere at this point was so febrile that Crookshank thought "a puff would have brought the Govt. down", whilst Amery noted "all except a few ultra-Government men utterly dismayed and disgusted". Fortunately for the government, the Speaker accepted the motion for the adjournment and ended the debate at 8.09pm. An MP who went back into the Chamber afterwards told Nicolson that Chamberlain was "white as a sheet" and David Margesson, the Chief Whip, "was purple in the face", both knowing that if a vote had been taken it would have brought down the government.

The immediate result was a Cabinet mutiny, with ten of its members in the Commons leaving the Chamber for an impromptu meeting in the Chancellor of the Exchequer's room. They then warned Chamberlain that when the House of Commons met at noon the next day, unless he could declare that an ultimatum had been issued and had expired, the government would fall. After further pressure, Chamberlain summoned the Cabinet to a midnight meeting which was stormy in every sense, as it took place during a violent thunderstorm. This meeting took the decision to deliver an ultimatum to Germany at 9.00am the next morning with a time limit of two hours, so that it would have expired before the Commons met.

On 3 September, for the first time ever, Parliament met on a Sunday. The Prime Minister broadcast to the nation from the Cabinet room at 11.15am announcing that no reply to the ultimatum had been received and consequently the country was at war with Germany, and he gave a similar statement when the Commons met at noon. Although the government had not fallen, the events of the previous day damaged Chamberlain’s reputation and were an important step on the road to his downfall in May 1940.

Sources

• Amery diary, J. Barnes & D. Nicholson (eds.), The Empire at Bay – The Leo Amery Diaries, Volume 2: 1929-1945 (London, 1988)

• Neville to Ida Chamberlain, 10 September 1939, Self, R. (ed.), The Neville Chamberlain Diary Letters: Volume 4, The Downing Street Years 1933-1940 (Aldershot, 2005)

• Channon diary, R.R. James (ed.), Chips: The Diaries of Sir Henry Channon (London, 1967)

• Cooper diary, J.J. Norwich (ed.), The Duff Cooper Diaries 1915-1951 (London, 2005)

• Crookshank diary, Crookshank MSS, Bodleian Library

• Nicolson diary, N. Nicolson (ed.), Harold Nicolson: Diaries and Letters 1930-1939 (London, 1966)

• Wallace diary, Wallace MSS, Bodleian Library