Immigration is a dangerous policy area for a banker to wander into unprepared.

It’s pulling apart Britain. The rise of anti-migrant sentiment is playing out on the streets and at the ballot box across Europe.

In the United States, masked members of the Immigration and Customs Enforcement are pulling illegal (and legal) migrants from the nation’s streets and businesses.

And here in Australia, immigration and its impact on our cities, house prices, infrastructure and crime has been a running debate for years that is being recharged by the Coalition, in a bid to find some political relevance after its crushing May defeat, talking about cutting the migrant intake by 100,000 a year.

Enter Commonwealth Bank boss Matt Comyn, one of the nation’s most respected business leaders, at a parliamentary committee hearing on Tuesday morning.

In relatively gentle questioning from Liberal MP Simon Kennedy about the interaction between migration and house prices and the nation’s infrastructure needs, Comyn volunteered his opinion that “something in the order of 180,000 per annum” was the right number of migrants.

“It gives both the Commonwealth and states the ability to plan for critical infrastructure, including housing,” he added.

The only problem, realised by those listening to Comyn’s testimony, is that Australia’s permanent migration intake has been around the 185,000 mark for the past couple of years. A cut of 5000 would be almost imperceptible.

Net overseas migration, however, has been much higher at 316,000 in the 12 months to the end of March. The government hopes to bring NOM down to 260,000 this financial year and then 225,000 from 2026–27 onwards.

Cutting NOM to 180,000 would be a massive deal with major economic repercussions.

It would also have major political ramifications given the standing of Comyn, who spent three days at the government’s economic roundtable.

NOM, which measures permanent and temporary movement of people in and out of the country and includes students and returning Australians, and permanent migration are not the same.

But that important nuance disappeared when Comyn earmarked a number while linking it to infrastructure and housing prices.

Comyn is respected for his thoughtfulness and willingness to speak plainly, which was on display for most of his appearance on Tuesday.

As he noted, skilled migrants will be pivotal to fulfilling the nation’s housing and infrastructure needs. They’re also vital to the finance sector. Without them, building projects and banks would come to a standstill.

Whichever figure Comyn was referring to – and the bank clarified it was the permanent migration number – it wasn’t the only nuance he missed.

Population growth – be it births or migration – is a key factor in property prices. But, as Comyn knows, there are others.

Credit growth for housing, which Comyn said needs to ease a little, has accelerated since the Reserve Bank started cutting official interest rates in February. Throw cheap money together with our tax system and state planning rules, and you end up with an Australian property market that is one of the most expensive in the world.

Migration is one of the world’s political fault lines. It’s probably not the safest place for a banker.

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