Calls from mobile phones now account for more than a third of the total amount of time spent on the phone, according to a report by communications watchdog Ofcom.

The report revealed that mobile phone usage is continuing to reduce the amount of calls people make on landline phones, with 9% of UK households now relying entirely on mobiles. This compares to 7% that just uses landlines.

The number of mobile phone subscriptions also increased last year, with competitive tariffs and demand for the greater functionality of Blackberrys and PDAs the main causes, the report added.

The amount of subscriptions to fixed telephone lines fell by 1.5% to 33.6m last year, Ofcom’s survey found.