Amid the political crossfire over last week’s injection of £39.2 billion more taxpayers’ money into Lloyds and Royal Bank of Scotland (RBS), one group of people was forgotten — the poor customers, of whom I am one.

The European Commission’s drive to improve competition by forcing the two state banks to sell off some of their businesses is laudable in theory but in practice customers face years of uncertainty over who will end up owning their mortgage or current account.

Businesses being sold is nothing new, of course — Lloyds Banking Group was created when it bought Halifax Bank of Scotland this year. However, Lloyds has to sell only 20% of its branch network and is being pretty tight-lipped about just how that will work. For sale signs will be hoisted over 185 branches in Scotland, 250 in England and Wales and 164 C&G offices. Online bank Intelligent Finance is also up for grabs.

The popularity of online and telephone banking means most current account holders no longer think of themselves as tied to a branch but all accounts are linked to one by their sortcode — even if you took it out over the web or phone. We could see a situation where your branch in your home town is sold off, even though you’ve lived and worked elsewhere for 20 years and do all your banking online — fine if you’re happy to move, frustrating if you’re not.

Lloyds points out that you can stick with it but that would defeat the object of reducing its market share and you would probably have to open a new account with a different branch — again, frustrating for long-term customers.

The sale of the C&G branches will include savings accounts and “certain” mortgages. Will that include my tracker at 0.17 points above Bank rate, or 0.67%, after the Bank of England kept interest rates on hold for the eighth month in a row?

Lloyds said last week only branch-based mortgages would be sold to another buyer; those taken out over the phone or with a broker would stay with Lloyds, which will keep the C&G brand.

However, brokers were told that in fact mortgages will be sold on the basis of whether or not they were “securitised” — packaged up and sold on to investors before the credit crunch hit. Lloyds denied this, but the whole episode shows the potential confusion.

This is crucial because my deal is a portable lifetime tracker — it follows Bank rate for life and I can take it with me should I move home. I clearly want to hang on to such a good deal but it would equally be in the bank’s interest to get me off it.

Any new buyer would have to honour the terms of the tracker but they could play around with the portability. C&G will let me take the rate with me as long as I borrow no more than 75% of the property value but a new lender could be far more cautious. They have form — Intelligent Finance recently told borrowers that they will no longer be able to take their deals with them if they need to borrow more, and from next April they will not be able to port their mortgages at all.

The break-up of the banking giant may bring much-needed competition for new customers but undoubtedly existing customers will pay the price.

As Ray Boulger from broker Charcol said: “The European Commission has looked at all this from a competition standpoint but it’s clear the practicalities for existing customers haven’t been fully thought through.”

Kathryn Cooper is editor of the Money section

Times Recommends

• How to sell your home in a downturn
• How to boost your spending power
• Unemployment benefits explained