There are a number of reasons that the UK’s prime ministers can be called presidential. For instance Blair and Thatcher were both dominant over their government they would often ignore what their cabinet said. The PM is also very much seen as the head of state Also the PM is very much a figure head and the media portrays him as the head of the party, the government and the party ideology. The PM if he or she has a majority in the House of Commons they can pretty much pass any law that they like as long as the whips are used to enforce that the party votes the way that the leader of the party wants.
Also Tony Blair was a very dominant PM, he would take his cabinet’s opinions in to consideration but quite often he would ignore what his cabinet had said and do what he wanted. For instance some members of his cabinet resigned as ministers over the Iraq war because Blair would not listen to them. But there is also an argument to say that the UK’s PM s are not presidential for instance the PM is part of the legislature and is therefore accountable to the House of Commons instead of directly to the people whereas a President is voted for directly by the people so the president is directly accountable to the public.
Although it could be argued that the PM is accountable to the people through the media for instance televised debates and coverage in broadsheet newspapers. The PM is very much a figurehead and this is the way that the PM is portrayed within the media, for instance when a parties policies fail or something goes wrong with the country it will invariably be blamed on the PM as he is portrayed as the head of the party and the government even if the thing that goes wrong has nothing to do with them they will still be blamed by the public and held accountable by the House of Commons.
In this sense the PM is more of a president than a Prime Minister. On the other hand the legislature and the executive is not strictly separate because the PM is a member of the legislature before they are a member of the executive and they are chosen from the legislature, whereas a president can only be a member of one of those things. For instance the President can not sit in Congress or in the Senate as well as being President people can only sit in one. The real UK head of state is the Queen but this is a ceremonial role as it is the prime minister who has the power.
When Gordon Brown was Prime Minister he wanted to give powers back to the Commons these included the power to declare war, he also wanted to curb the power of the whips and he wanted all select committees to be voted by MP s instead of chosen by the PM. In conclusion I would say that the Prime minister is presidential purely because of the amount of power that the PM has over the country, as long as he has a majority in the House of Commons then the PM can exercise all of his power and it is almost impossible to stop him the government outnumbers the other parties that will want to try and stop the legislation set out by the PM.