Bank executives will meet this morning to consider formally lifting the rates charged to all variable mortgage customers. An increase of 0.10 percentage points would add $19 to the monthly cost of servicing a $300,000 loan.

But on Monday, with minimal fanfare ahead of Tuesday's Reserve Bank board meeting, the bank lifted the effective rate charged to new high-value mortgage customers.

Previously, new customers planning on borrowing at least $500,000 were were offered a discount of 100 points off the standard variable mortgage rate, taking the rate charged from 7.3 to 6.3 per cent.

On Monday the discount was cut to 90 points, lifting the rate charged to new customers to 6.4 per cent.

''It means anyone who has applied for a $500,000 loan from Monday will be paying $31 more per month than anyone who borrowed the week before,'' said Canstar senior financial analyst Mitchell Watson.

''Existing customers are still paying the same rates so it doesn't make the ANZ that much money but it is a sign that it is tightening.''

The move comes as the Financial Stability Board, which is based in Switzerland, expressed concern about Australia's relatively generous government backing of bank deposits.

Australia has one of the broadest depositor protection schemes in the world. With a cap of $250,000 the scheme is equal to only the US.

''Although a high coverage level reduces the incentives for depositors to run, adequate controls are needed to ensure a proper balance between financial stability and market discipline,'' the Financial Stability Board said in a global review.

The ANZ pledged in December to no longer closely follow the Reserve Bank in adjusting rates, considering the question independently on the second Friday of each month.

Evans & Partners banking analyst George Gabriel said of all the big banks the ANZ was under the most pressure to tighten rates.

''It's the only major bank whose margins shrank in the second half of 2011,'' he told the Herald.

''Westpac and Bendigo Bank are talking about following the ANZ but it is the ANZ that needs to move rates the most.''

Mr Gabriel said on balance he thought the ANZ would not move today because it would not want to ''expend all its political capital unnecessarily''.

The National Australia Bank promised this week that its rates would be lower than the other big three for the duration of the year. Bank of Queensland said yesterday it would hold its rates steady until the next Reserve Bank board meeting regardless of what the other banks did.