From what I read/heard.... in the UK the Prime Minister and the Cabinet make the budget... it is NOT voted on by the Parliment... so much easier to do what you want...
Now, if you do something that is so horrible... then they can have a vote of no confindence and 'collapse' the gvmt.... not exactly sure how this works.... just some of the things I heard when there.... Parlimentary gvmt is a lot different than what we have...
You are correct. However, a vote of no confidence is really only possible in a minority government, and there have only been one or 2 of those in the past 50 years and they never survive long. A minority government is possible in systems with more than 2 parties. At the last election no one party had more votes than all the other parties combined so it was possible for the Tories to form a minority government, but they knew that they could always be out-voted on contentious issues, and were vulnerable to a vote of no-confidence, so instead they formed a coalition with the Lib-Dems so that the government cannot be outed before the next election unless they have a great many defections.