A national campaign to publicise the switchover help campaign is to launch this weekend.

Two trails - one featuring an elderly lady who tries to match-make between a visitor and her digital equipment installer, and another featuring a blind man who jokes that his guide dog can't install a digibox with his paws - will run on BBC One and BBC Two from Saturday, with the first going out on BBC One at 16:29.

"People are beginning to hear more about the digital switchover which will be taking place in different regions between now and 2012," said Peter White, chief executive of the scheme. "This will be straightforward for many who are already switching to digital TV but a small number of people will need extra assistance in making the change.

"Even though this is some time away for many, we want to reassure everyone eligible that when that time comes practical help will be available."

The scheme is available to people aged 75 or over, those who are registered blind or partially sighted, and those who receive, or may be eligible to receive, disability benefits. For £40, participants receive help converting one of their TV sets to digital. The service is available for free to eligible people on pension credit, income support or income-based jobseekers allowance.

In the Border region, Sky won the contract to provide its digiboxes and installation services through the scheme, a decision that was criticised by one MP and some industry groups as being "unfair".