National Party leader Simon Bridges is sitting in his office with his deputy Paula Bennett and MP Mark Mitchell, who is regaling them with his "dad jokes".

They include pearlers such as "two goldfish are in a tank. One says to another 'how do you drive this thing?'"

Bridges may well have wondered the same thing about being Leader of the Opposition.

Bridges is clutching a Young Nats' branded coffee cup.

He's ordered 20 and has a plan to sell some on in his Tauranga electorate for $4 more than he paid for them. "Make a tidy wee profit. Let's hope that doesn't result in a police investigation."

Caveat emptor: the cups have a tendency to leak.

"The problem is the lids don't go on very well, so I think there's about a 48 per cent chance of getting coffee on myself."

He laughs with some gusto when it is suggested the same problem applies to his caucus - the lid hadn't been on very well.

It was the leak of his travel expenses that was one of the triggers for his current plight – a leak he has blamed on Jami-Lee Ross although Ross denies it.

Ross has admitted questioning Bridges' leadership and polling, actions deemed as acts of disloyalty by Bridges and National MPs and which was one of the prompts for Ross to be put on leave.

Bridges admits there is still some public fascination with the matter, but he believes ultimately the public want National to move on and focus on other issues, such as the fuel taxes, Karel Sroubek and "things that have an impact on the country".

What Bridges means is he wants to move on himself. The release of a new tape on Monday did not make it any easier, but it will be of some consolation that it dominated the news for one day.

The return of Ross, when that day comes, will be another trial.

Bridges new catchphrases on questions relating to Ross are "I am done talking about this" and "National is moving on."

The massive 56-strong National caucus was a force Bridges' predecessor Bill English said would be "the strongest Opposition party that Parliament has seen."

They have now shrunk to 55, but English wasn't completely wrong.

The case of Czech Sroubek securing residency could not have come along at a better time for National.

They have been hammering at the case.

Mitchell has proved good for something other than dad jokes, getting information on Sroubek National has used to embarrass Immigration Minister Iain Lees-Galloway in the House day after day.

So, too, with its attacks on fuel taxes.

Question Time has become appointment viewing again. While interest in the latest tape release by Ross lasted one day, Sroubek keeps going.

It must be infuriating that as National starts firing in Opposition, it has also shot itself in the foot, courtesy of Ross.

But it is the lot of Opposition leaders to have their obituaries written early, and often.

On that Bridges says "I am enjoying proving them wrong."

"I look at this year and I believe National under me has set the agenda, whether it's been business confidence, the economy, cost of living, law and order, even in the last couple of weeks in forcing the Prime Minister's hand on fuel taxes, on Sroubek.

"I feel very confident we will end the year dominating the news with things that matter to New Zealanders and where the Government has shortcomings."

He is also confident he will still be leader.

During the last leadership run-off, Judith Collins set herself the mark of 35 per cent in the polls as the point at which a leader should go.

When he is asked whether he would jump or try to ride it out if the party dropped to that level on his watch, Bridges simply insists that will not happen.

"It would only be natural that in the light of something like the Jami-Lee Ross episode, there is a temporary questioning, but I've got no doubt as we've got back on to issues such as the fuel tax and Sroubek we are in good shape."

The last One News Colmar Brunton poll was taken over the week the Ross drama was breaking – and National dropped just 2 to 43 per cent.

Bridges had dropped to just 7 per cent and had already been struggling in the poll for preferred Prime Minister – one of the reasons Ross was "undermining" him to begin with.

Bridges will not reveal what National's internal polls show now, but says the party is still in the 40s despite reports that Labour's internal polls had it in the high 30s.

"The real story is how so many New Zealanders get that this is a transitory thing involving one MP, has been handled right, and National is still the party that focuses on the things they want to where the Government isn't," says Bridges.

"Before this, we were making the running and doing well but this has tested me, it has given me a sense that actually, in the real difficult stuff, I'll do what's right and ultimately I reckon that's what New Zealanders want from a leader."

He was "heartened" by the way his caucus swung in behind him and said though public perceptions of a leader were important, so was policy and a party's plan.

They would start to see more of that from next year.

"The end" for Bridges will likely depend how long caucus can keep its lid on.

Bridges has had to apologise to one of them – Maureen Pugh – for his colourful analysis of her performance as 'f***ing useless" in a taped conversation with Ross.

Asked whether he has the florist on speed-dial to send apologetic bunches of flowers, he points to his Young Nats cup again.

"Maureen deserves flowers. What she got was a fulsome apology from me.

"Maybe she'll get a Young Nats coffee cup, hahahahahaha, and she won't have to pay $12. I'm feeling generous. I owe Maureen. So $5 will be fine."

Lucky Pugh.

One of Bridges' saving graces may be that he can still manage to laugh at his plight, though he admits sometimes that was put to the test.

"I've got no doubt now I am a strong leader. As twee as that may sound, I've been tested and I've come through. The caucus knows that, they've seen everything."

Steven Joyce was National's "Mr Fixit" in Government, charged with mopping up messes where required or taking the hit himself when it could not be tidied.

On the day Bridges spoke to the Weekend Herald, Joyce was tweeting about his efforts to put together a barbecue.

The summer barbecue has been code for plotting a leadership change since the mid-1990s when former Labour MP Phil Goff hosted a barbecue at which there was reportedly plotting against the-then unpopular Helen Clark.

Clark stared Goff and her low personal polling down and went on to become Prime Minister.

When Joyce's efforts are mentioned, Bridges quickly says there is "no need" for barbecues in National. But Clark may well now be Bridges' beacon of hope.

The next day Bridges texts to advise he has sent Pugh one of those leaky coffee cups – free of charge.