There are no black or minority ethnic (BME) staff reported in the top seven pay levels of the House of Lords administration, according to data obtained by the BBC.
All 89 of the most senior employees whose ethnicity has been declared are white (there are also three senior staff who have not stated this information).
In contrast five out of six workers in the lowest pay grade are ethnic minorities.
The Lord Speaker Baroness D'Souza, a cross-bench peer who chairs House sittings, described the data as "disappointing". She said she would be monitoring progress from now on.
Lord Ouseley, formerly chair of the Commission for Racial Equality, warned that the House's top positions form "a 'no entry' area for BME employees".
Catering and retail
The figures have been released by the House of Lords in response to a BBC Freedom of Information request about the ethnic profile of the House's own workforce, numbering nearly 600, from clerks to catering.
It does not include researchers and other staff directly employed by peers themselves, or bicameral staff shared with the Commons.
The seven top pay bands range from £49,083 to £176,226 including the senior clerks and managers of administrative workers. The maximum salary in a pay range containing a declared black or ethnic minority employee is £42,686.
The FOI request revealed black and minority ethnic workers are overwhelmingly concentrated in the House's lower pay bands, with over half the BME workforce employed in housekeeping, catering and retail.
Five out of six workers at the lowest pay level are BME, earning between £17,135 and £17,744 a year. This is just above the annual London "living wage", which based on the Lords' 36 hour working week would be £17,128.80.
Overall, 13% of Lords staff have declared themselves as BME. London's working population is currently 37% BME. But in the chamber itself only 6% of peers are ethnic minority.
The ethnic profile of House of Commons staff follows a similar pattern to the Lords, but is less extreme. It has just 6% BME representation in the top seven pay levels, with 40% at the catering level.
The Commons launched a diversity scheme in 2012, aiming to improve minority representation at senior levels. It issues an annual report containing ethnic data of this sort.
But the House of Lords has no equivalent formal published strategy with regular monitoring data.
A Lords spokesman said: "The House values diversity in its staff and is working hard to improve its record in this area. Our record on diversity has not been good enough but is improving and will continue to do so."
The Lords administration argues that change at senior levels is slow because of the House's relatively low staff turnover rate, which is well down on the national average.
The House has revamped its application process to promote equality and says it is widening access to development opportunities.
But Lord Ouseley accused the House administration of recruiting and promoting from sources that are too restricted.
He said: "If it wants to achieve diversity at the middle and higher pay grades, the Lords will have to cut away from the sources which deliver more of the same and pursue avenues that would enhance the gathering of talent from a bigger and more diverse pool of talent.
"It will only ever change if there is a political determination to make equality a reality, and that is not about to happen."
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