The cash crisis affecting this season of The Block has worsened as Scott Cam delivers the toughest blow yet.

The Block host Scott Cam delivered a brutal reality check to contestants during last night’s episode, as the cash runs dry and it becomes even more apparent that several of this season’s couples will struggle to finish their build.

Cam couldn’t have been more blunt: “We will flog these houses unfinished,” he told the couples, leading to more than a few tears from some.

It was the latest tense development in a cash crisis that’s loomed large over The Block in recent weeks, as contestants tackle a renovation project far larger than any other season.

The always honest Cam spoke to news.com.au today about a Block season unlike any other.

So Scott, let’s get straight to the point: Is this year’s Block unfinishable?

At about week three we realised that it was a bit too big this year and we’d have to push them a bit harder to get it through. But we told them about budget issues from the start, and they just didn’t listen. I gave them extra money, and then I gave them extra money again … I’m dry now. The network will not give me any more money.

We probably won’t do a Block this big ever again. Next year we’ll scale back. Even I’m under the pump — it was tough on everybody, the crew included.

RELATED: Is The Block setting contestants up to fail?

RELATED: Scott Cam, that was just cruel

But I told them all from week one: You get $250,000 to do 14 spaces, divvy it up. There’s plenty of money to be won along the way in challenges too. And you can bargain shop — buy some cheaper items that look exactly the same.

You mentioned in last night’s episode that your own Channel 9 bosses had refused any more handouts. Have they been tense negotiations?

The network is always taken by surprise when we ask for more money. It’s never an easy conversation! But we said, it’s bigger than we anticipated in terms of costs. We realised we’d have to give them more money or no one finishes. We gave them more money, they’re all cheering — and then they all start spending again. That’s the problem! It’s pretty silly.

But people do start budgeting when they get desperate. Some of it does sink in — but not much.

Do you think some couples have been working under the assumption they’ll keep getting bailed out when money gets tight?

There’s absolutely no more money. The network was reluctant to give us the last bit of money. We extended the show by another week so we could say that they needed more money, and (Channel 9) accepted that — but they said, that is IT. The network says, ‘Well, if they don’t finish, they don’t finish’. So now it’s our job to get them across the line. I only need one team to finish.

It seems to be dawning on some of the couples now: They may walk away with nothing.

Well, there’s no guarantee of life-changing money on The Block. You’ve got to do everything right and have all the planets aligned. Some of the guys this year strolling along just thinking they’re doing a TV show and they’ll walk away with half a million bucks — that’s never been the case.

You’ve got to have a good real estate agent, budget extremely well, have a great building team, have a good auctioneer, have a good property market at the time. You’ve got to design a house that emotionally connects with the buyer. And then maybe you’ll win half a million or $200,000. And they all know that, but … they forget. They forget.

Forty-five thousand couples apply for The Block, and these five couples were chosen. There’s been a bit of whingeing this season, and I’ve said to them many times: If you’re not happy, if you don’t like it, well, we’re not curing cancer here — go home. We’ll get one of the other 45,000 couples to finish.

The contestants seemed on the verge of mutiny the other week when they were told how little money they had left.

They can do a mutiny if they like; it’s not going to get them anywhere. OK, see ya! Go home. It wouldn’t be the end of the world if there was a walk-off. It’s a TV show and it’s been done by many people before, who’ve done it successfully, so I don’t see why these guys can’t. Having said that, they’re working so hard, under tough conditions, and I’m so proud of them. Of course they have low moments; we’re there to talk them back in.

There’s no Block this Sunday — the show continues 7.30pm Monday on Nine.