Clayton Mitchell's crusade to have big sports games televised free-to-air has reached a crucial stage.

The Tauranga-based New Zealand First MP's proposed law is scheduled to have its first reading in Parliament this evening, ending with a vote that will either see it blocked or allowed to proceed. Under the proposal, taxpayers would fund the broadcasting of "nationally significant" events involving rugby, league, netball, cricket and other codes.

The idea has been praised for letting more people watch sports on television but has been criticised for making taxpayers foot the bill and for potentially reducing the amount of broadcast money that major sports teams can demand on the open market.

Mr Mitchell yesterday said he believed it was "completely wrong" that people who couldn't afford a Sky subscription missed out on watching big games.

"Having live sport on television is not a big ask," he said. "New Zealand had it before, and our bill will make sure we can have it again."

However, the bill is almost certain to damage Sky if it becomes law.

The broadcaster's communications director, Kirsty Way, said Sky paid sports teams $120 million last year for the rights to broadcast their games. The teams obtained that money in an open and competitive market which would vanish under Mr Mitchell's proposals.

"It's not something we do agree with," she said. "There's questions over how it will be funded - diverting money away from healthcare and education."

Mr Mitchell submitted the bill in 2014. In December, it was randomly selected to go through processes that could see it become law.

Examples of proposed free-to-air events:

- Rugby World Cup games
- Domestic All Blacks tests
- Super Rugby final
- Netball World Cup matches
- Cricket World Cup matches
- Domestic Black Caps one-day cricket games
- Rugby League World Cup games
- All Whites World Cup football games
- Australian National Basketball League Grand Final
- Summer Olympic Games
- Winter Olympic Games

Source: Broadcasting (Games of National Significance) Amendment Bill