Poet Laureate Andrew Motion says writing for the British royal family is a "thankless" task which is "incredibly difficult".
Andrew won the prestigious post - which sees him write poems to celebrate major state and government events, such as royal birthdays and weddings - nine years ago, but claims it has only served to give him writers' block.
Speaking to an audience at the Ealing Arts Festival in West London, Andrew said: "The job has been incredibly difficult and entirely thankless.
"It has been very, very damaging to my writing. In fact, I dried up completely about five years ago and can't write anything except to commission. I thought the poetry had all gone, but I feel some of it is still there and may yet return.
"Writing for the royals was a hiding to nothing."
The 55-year-old writer also claimed he has no idea whether Queen Elizabeth is happy with his work - which includes a rap-style celebration of Prince William's 21st birthday.
He said: "The queen never gives me an opinion on my work for her. The last thing I did was for her diamond wedding anniversary. I came up with a poem and had to go along to Westminster Abbey. It was read beautifully by Dame Judi Dench.
"Afterwards the queen stopped me and said, 'Thank you.' But I have no idea if she really liked it."
Despite telling Britain's The Daily Mail newspaper he thought the job was a "thankless" task, the poet added the role had some plus points.
He said: "Some of the writing responsibilities are thankless, but there are other things about the post which are extremely valuable - such as the chance it gives to speak up for poetry."