"There is a benefit in being part of a strong brand and collective, especially in this economic climate," said The Westminster Collection chief executive René Dee.
"We have a fairly ambitious two-year plan and have made the decision to become more representative of Westminster as a borough, which extends into the West End, up to Kilburn and across Paddington and Fleet Street. We have 23 venues at present and by the end of the year I predict we will have 30."
To join The Westminster Collection a venue has to offer something unique, because the venues are chosen to complement each other rather than compete.
The next annual showcase takes place on 5 February at Central Hall Westminster.
St Stephen's Club also recently joined The Westminster Collection this week. To see story