BT has been criticised employing for what some are calling "stealth tactics" by the manner in which it is seeking to lock small firms into new contracts.

The Forum of Private Business claims that the telecommunications giant will switch all customers with BT's business PSTN lines to its Business Line Divert service unless they opt out now.

According to the FPB, the switchover - set to take place tomorrow (Thursday) - will commit customers to a further 12 month deal.

The forum says BTs claims that it has written to small firms to inform them of the change is not good enough and does not amount to consent.

Phillip Moody, the FPB's senior member services representative said: "This is another example of a big business imposing unfair terms and conditions in a rather underhand manner.

"Business owners should be very careful and scrutinise their terms and conditions when they are signing up. It is imperative that they take action now to avoid being tied into this contract."

He added that the move has also been criticised by other telecommunication firms including Chess who levelled the "stealth tactics" accusation at BT.

Last week the FPB reported the findings of a Access Markets International study which found that smaller firms in the UK spent £20 billion on IT and telecoms in 2007.

According to a recent survey by Connect, the two biggest IT headaches for businesses were 'everyday hassles with IT' (37 per cent) and 'security concerns' (32 per cent) In a recent survey of SMEs for Connect, the two most important benefits of outsourcing were 'guaranteed response times' and 'allowing in-house IT staff to concentrate on more strategic issues'.