Whether it is actress Emma Watson or anybody in the UK's Labour Party, there isn't a British person Israeli officials or ex-officials won't step forward to publicly attack if they sympathise with with Palestinian Arabs.
What does Britain have to do with Israel?
Prior to the creation of Israel, that part of the world was known as the British Mandate for Palestine and, later, Mandatory Palestine. The British were present in the first place to secure a Jewish homeland, as per the 1917 Balfour Declaration, and this promise was fulfilled when the State of Israel came into existence in 1948. However, things did not go as intended.
Britain never intended to create a state where human rights of Arabs would be undermined, or provide justifications for mass displacement and ethnic cleansing of Arabs. It did not support violating the rights of Muslims to worship as they have always done in their holy sites. In 2017, Britain acknowledged that the Balfour Declaration should have protected Palestinian Arabs' rights.
Britain made a mess of things in the territories of its former empire, drawing borders incorrectly. Poor understanding of the people of the controlled regions precipitated a number of current conflicts. Dubious conflict-prone states such as modern India and Iraq were created arbitrarily, often at the stroke of a pen, with no interest in how history or local culture might cause tension. Britain has not atoned for the situation.
Israel's doubts about its own legitimacy
Knowing their country was created by the British, Israelis actually seem to cower at our every utterance. Perhaps their terror is that the British will apologise for creating that state, somewhat undermining the legal basis for its existence.
The best advice to the Israelis is that they should leave Britain alone and stop being so interested in our opinions. If they continue to aggressively lobby for the British to support Israel, in their hopes to avoid the nightmare of British disavowal, Israel is most likely further irritating many British people and drawing their disfavour.
Anti-Israel (but not necessarily anti-Semitic) views are commonplace in the UK, and a large cause of that could be the strained and aggressive attempts of the Israelis and their sympathisers to influence our point of view. The strong movement within the Labour Party that emerged under Jeremy Corbyn was partly due to his principled support for the international cause of Palestinian rights in the face of significant attempts by morally dubious Israel-supporters and Blairites to hinder him.
Israel's unwarranted concern
The next time British people, even top British figures, say something critical of Israel, Israel's most dignified reaction would be no reaction. However, with the kind of insecurity they have about the legitimacy of their state, it is more likely that they will continue whining more than any other country in the world would, triggering even more attention and criticism in the future.
When the Israelis express so much concern about international attitudes, and especially attitudes in Britain, it makes their country look new, floundering and half-legitimate. Maybe that's how it still is. Maybe they are trying to tell us that they don't think their country's existence is secure, and that mere cold words from Britain might be enough to create chaos.