How can I approach this essay question: ‘MacDonald betrayed the Labour Party during his second ministry, 1929–31.’ How far do you agree?

Before getting into writing you should start by analysing the question and making sure you know what it's asking you to do. In this case, you need to have some idea of how a politician could 'betray' his party. The best answers will make this clear in their introduction, maybe offering a criteria for a political 'betrayal'. Example: 'It will be considered that MacDonald betrayed the Labour Party if he abandoned its core ideology and worsened its electoral success'The rest of the essay could look to answer that initial criteria, showing the examiner that you understand the complexity of the question and helping your structure. It would be easy to focus only on MacDonald's decision to form the National Government in 1931 as an aspect of his betrayal. However, the question notes the dates '1929-31' so its essential that you discuss his policies and actions as Prime Minister before this. Here are a few ideas:Did MacDonald's policies adhere to the Labour Party Constitution 1918? The Housing Act and benefit reform were examples of social reform, but there was no major nationalisation or redistribution of wealth which may suggest he betrayed his party's ideology.But was socialist reform possible at this time? The party lacked a majority and the House of Lords blocked many reforms - perhaps adhering to Labour's ideology was not politically viable and so not a betrayal.Did the decision to form the National Government help the party? Labour were kept out of power until 1945, and MacDonald choose to leave the party rather than negotiate a solution with his cabinet. This would constitute a betrayal.Or was this choice necessary? Britain faced an economic crisis which required national unity and his cabinet seemed reluctant to shift its position. You could argue that forming the National Government was necessary and that his cabinet left him no other choice.
As ever, remember to include two points of view and make your overall conclusion clear.