It can't happen here

As we all marvel at the insanity of the US government shutdown, a few people are asking whether it can happen here. The short answer is "no". In Westminster systems, matters of "supply" (of funds, to keep the government operating) are matters of confidence. Losing such a vote would mean that the government had lost the confidence of the House, automatically triggering the caretaker convention and either a coalition realignment or elections. The US only has this problem because they have such a strict separation of powers, which prevents such automatic political circuit-breakers.

The slightly longer answer is "possibly", in that if something (a badly-timed loss of confidence, or a natural disaster) occurred at the end of a financial year, before a Budget or Imprest Supply Act (a temporary spending authority to span the gap between the introduction and final passage of a Budget) was passed, then appropriations could end, making it illegal for the government to incur expenses for most things ("most things" because some appropriations are multi-year, and some areas of spending have permanent authority). Even then, the government could pay its debts and deal with emergencies.

The even longer answer is that it is highly unlikely. Firstly, because unlike the US, our political parties are responsible and do not view the continued operation of the government as something to be held hostage. In the event of a badly-timed loss of confidence, I have no doubt that they would pass an Imprest Supply Act to ensure lawful spending pending the formation of a new Government (which would ironicly demonstrate confidence in someone, but that's where constitutional paradoxes get you). Secondly, because if that didn't or couldn't happen, they might just keep spending money on legal obligations and necessities (e.g. people's wages, welfare benefits), if necessary by declaring a state of emergency (justified on the basis that an inability to pay for basic health and law enforcement may cause loss of life or injury or illness or distress and endangers the safety of the public), and rely on a retrospective validation to clean up afterwards. Which, again, I think would be forthcoming. Unlike the US, our constitution (both legal and cultural) is a flexible thing, and can cope with such eventualities.