A new edition of the book, a who's who of the UK's most patrician citizens, is published this week for the first time in nearly 30 years.

In another first in its 173-year history, the 106th edition will include details of illegitimate children as a matter of policy.

Editor Charles Mosley said: "With so many children now being born out of wedlock, it would be absurd to ignore the fact."

The taboo on illegitmate children was broken 15 years ago by Burke's rival publication, Debrett's Peerage and Baronetage.

Burke's Peerage and Baronetage, to give it its full title, has not been printed since 1970 because of printing costs.

The new rule will enable the editors to avoid a repeat of the farcical situation when Viscount Drumlanrig was omitted because he was born before his father, the Marquess of Queensbury, married his mother.

'Facing modern reality'

Historian David Starkey said the decision to recognise children born out of wedlock was "a combination of a good publicity deal on the one hand and facing modern reality on the other".

The 106th edition of Burke's, which comes in two weighty volumes, will cost £295 and is unlikely to rival Lord Archer's bestsellers in sales terms.

But Mr Mosley is hoping it will prove a must with genealogists around the world and curious peers.

He said: "The print run was 4,000 and we have called it a first impression, which may seem optimistic, but we have already been overwhelmed by the level of interest.

"We are waiting to see if people put their money where their mouth is."

With the government vowing to do away with hereditary peers it may seem that Burke's and Debrett's are living on borrowed time.