The documents were prepared for the Westpac board. The first branch of the Bank of Melbourne is due to open within weeks.

The documents are likely to embarrass Westpac's chief executive, Gail Kelly, in her high-stakes push into the Victorian market as well as raising questions about the bank's $11 billion St George acquisition.

The revelations are expected to rekindle memories of Westpac's ''banana smoothie'' animation it produced in late 2009 as a way to explain to mortgage customers how its super-sized interest rate rises was similar to the price of bananas going up.

Last night a spokeswoman for Westpac said the documents were not an accurate representation of the business plan or forecasts for Bank of Melbourne, as they were presented to the board 12 months ago.

''It was not the business model put to the Westpac Group board for final approval and therefore should not be relied on as an accurate source of information,'' the spokeswoman said.

The Westpac board agreed on the Bank of Melbourne and associated business plan in February. The overhaul of the St George franchise, dubbed by the bank as Project Crest, seeks to rebuild market share across Victoria.

The aim is to offer customers a strong regional bank alternative - a bank that is not one of the big four brands.

Westpac detailed plans in March to rebrand 34 Victorian St George branches. It also said it would triple the size of the Bank of Melbourne network over five years.

The former Westpac chief executive David Morgan controversially dumped the Bank of Melbourne brand in 2004 despite a promise to maintain the business that it bought for $1.5 billion in 1997.

The document, presented to a two-day Westpac board meeting last July, admits St George has ''a small position and a relative weak performance'' in Victoria.

It notes that a ''lack of brand awareness and lack of a branch

network'' were among the key reasons why St George has failed to gain traction. Women aged between 40 and 59 who regard themselves as professionals have been identified as customers ripe for poaching for the bank.

And in a suggestion a new banking war could be in the offing, Westpac has forecast that most of Bank of Melbourne's new customers are likely to come from Commonwealth Bank.

However, it also admits the bank could snare as many as 100,000 customers from its flagship Westpac bank, a process known in banking circles as cannibalisation.

The document suggests the revival of the Bank of Melbourne brand will win immediate support from ''government and influential Melbourne identities''.

It also noted Melbourne's media will respond well to the brand resulting in ''free PR'' around the launch date.

The documents also came with a pointed warning:

''Handle the … brand with absolute care and discretion - Melbourne is a provincial global community and many feel that they own the brand''. However, in rolling out the brand, it reserves some criticism for Sydney, describing the city as ''bright and brash''.

The Westpac chief executive, Gail Kelly, has said the Bank of Melbourne is a key part of Westpac's multi-branded strategy.

In South Australia, St George operates under the BankSA brand.

Rivals have already taken aim at the planned rebadging exercise.

The chief executive of Bank of Queensland, David Liddy, recently said that most bank customers would know that Bank of Melbourne was owned by a big-four bank.