Thomas is the most requested "historic" voice on the site

Additions include Siegfried Sassoon reading his poem, Everyone Sang, plus three works by Philip Larkin.

"We are delighted to facilitate the recovery of these recordings," said project head Paul Gerhardt.

The free archive was launched in 2005 by UK Poet Laureate Andrew Motion and recording producer Richard Carrington.

According to Motion, the archive had gone "from strength to strength" in its first year online and had become "an incomparable resource" for pupils, students and teachers.

"The new voices added to celebrate our first anniversary can only solidify and increase its value," he said.

'Not in decline'

Numerous requests for Thomas have prompted the addition of two of his works - A Refusal to Mourn the Death, By Fire, of a Child in London, and In My Craft or Sullen Art.

Walter de la Mare also makes his debut, reading Thomas Hardy - a poem celebrating a visit its author made to Hardy's Dorset house in June 1921.

In all 14 poems by eight authors have been added to the website. The total archive contains more than 300 recordings.

"We often read reports in the newspapers and elsewhere saying that the audience for poetry is in decline," said Motion.

"The very large number of people who have used the archive during the last 12 months prove otherwise."