ANDREW Thorburn, the new chief executive of National Australia Bank, is already helping ensure the institution's top brass retains its richly-deserved reputation for bluntness when it comes to its Glasgow-based Clydesdale operation.

Mr Thorburn certainly left no-one in any doubt about just how much he wanted to get shot of NAB's UK business. He declared that it was an "absolute priority" for NAB to exit the UK market-place.

It has been fairly evident, from a raft of forthright remarks from NAB executives over the years, that the Australian bank would jump at the chance to offload Clydesdale and its sister Yorkshire Bank. So it is not as if management of Clydesdale, and the bank's thousands of employees, did not know which way the wind was blowing.

However, what Mr Thorburn appears to have done is started a clock ticking for the disposal of the UK operations. And Australian investors and sector analysts, who have for years now been griping about Clydesdale and Yorkshire, will be looking for him to deliver on his commitment in fairly short order. History would suggest Mr Thorburn has kicked off his stint at the top by setting himself an extremely tough challenge.

If there were any buyers for the Clydesdale and Yorkshire operations, you would think they might have pitched up by now.

The dearth of buyers for banking assets, especially those with operations concentrated in certain parts of the UK, has been evident in the failure of Royal Bank of Scotland to sell branches and assets which are now to be floated as Williams & Glyn.

RBS lined up a deal with Santander to sell these operations, which are concentrated in north-west England, but this fell through.

Lloyds Banking Group, for its part, failed to conclude a sale to a trade buyer of its "Verde" assets, which included the Lloyds TSB Scotland branch network and Cheltenham & Gloucester outlets. These assets have since been floated successfully on the UK stock market as TSB.

To be fair to Mr Thorburn, he appears to be well aware that a search for a buyer of Clydesdale and Yorkshire could well prove fruitless.

In NAB's latest full-year results, published yesterday, he says: "Our clear focus is on our Australian and New Zealand franchises and providing a better customer experience, and as a result we need greater urgency dealing to our remaining low-returning assets.

"In relation to exiting UK banking, this means we are now examining a broader range of options including those provided by public markets."

Perhaps Mr Thorburn has been encouraged by Lloyds' flotation of TSB, and believes NAB can follow suit with its UK operations.

However, it is important to remember that the new TSB, unlike many of the established UK banks, has not had to deal with huge legacy issues such as the mis-selling of payment protection insurance (PPI) and of some complex business loans.

NAB, while its UK operations have been far from alone in having had to make huge provisions for customer redress amid these mis-selling scandals, appears deeply unimpressed about all of this just the same.

Mr Thorburn says in the results: "While our Australia and New Zealand franchises are in good shape, it is disappointing to record a full-year result that includes 1.5 billion [Australian dollars] after tax in UK conduct provisions and other impairments."

The shadow of the PPI and business loan scandals may loom large over any flotation plans.

And that is not the only issue. This month, we have seen Virgin Money delay a planned flotation because of volatile stock market conditions. Fellow "challenger bank" Aldermore has also pulled away from a flotation.

It is far easier to envisage a flotation of Clydesdale and Yorkshire, acquired by NAB in the late-1980s and early-1990s, than a conventional sale.

But that certainly does not mean such a flotation will be quick, easy, or a foregone conclusion.

You would have to say that NAB executives, past and present, have hardly been talking up Clydesdale and Yorkshire.

With regard to NAB's UK business, The Australian Financial Review recently quoted Mr Thorburn's predecessor, Cameron Clyne, as follows: "I spent six years of my life on it. They'll get out of there eventually."

Six years is a long time.

"Absolute priority" suggests Mr Thorburn does not want to spend six years of his life on the UK operations. But Mr Clyne has signalled that would not have been his choice either.

NAB's 7,100-strong UK workforce, about 3,700 of whom are in Scotland, have had more than their fair share of uncertainty over those six years.

Mr Thorburn has given the impression this uncertainty might at long last come to some kind of an end, for better or worse, sooner rather than later. By doing so, he will have whetted the appetite of investors in Australia keen for NAB to get out of the struggling UK economy.

But he should not underestimate the length and likely nature of the journey in terms of putting his talk into action. And he could face some sharp-tongued criticism in Australia if he is unable to deliver, and fast.