The programme could make Midshires one of the biggest supporters of charities and community projects in its catchment area of the Midlands, Liverpool and the South-west and among building societies generally.
The figure of pounds 1m-plus compares with just pounds 51,000 that the society gave last year, a similar figure to a number of other medium-sized societies. The Halifax gave pounds 1.9m.
The society said its new community investment strategy, which could cost up to 2 per cent of pre-tax profits a year, was aimed at building customer loyalty as well as showing itself as a caring corporate citizen.
But analysts speculated that the proposals meant more and put forward three possibilities: they are a precursor to flotation; a way of encouraging any predator to keep the Midshires brand and branch network; or a way of softening the blow to members and local community of a predator closing down the society.
The society's board will decide on the level of funding this autumn and choose between setting up a charitable foundation or joining the PerCent Club, a group of businesses that donates at least 0.5 per cent of their pre-tax profits to good causes. The society denied that the thinking behind any charitable foundation was to use it as a "poison pill" against future predators.
As part of its conversion from mutual status earlier this year, Northern Rock proposed a charitable foundation holding voting rights over 15 per cent of the would-be bank's shares.
Officially, Midshires says it is committed to mutuality, but insiders admit the society is keeping its options open. Analysts believes its primary wish is to be bought by a bank, but to be kept as a stand-alone mortgage subsidiary, like Lloyd's TSB's Cheltenham & Gloucester.
Unlike rivals, Midshires has not launched a mutual benefits package aimed at emphasising to members the value of it remaining a building society.
But it said its community strategy, which would come in next year, would be a "modern-day expression of a building society's roots". The programme would focus on social projects in the society's catchment area.
A spokeswoman for Business in the Community, the charity which runs the PerCent Club, said a community programme worth in excess of pounds 1m a year was significant. The biggest giver last year, BT, had a programme worth pounds 15m.