For years, foreign tourists in London have scratched their heads wondering why it’s so tough to see a show on Sundays. But West End theater performances on the seventh day are poised to become the rule rather than the exception.

After a two-week consultation period with Equity members in the West End that ended Oct. 3, management body the Society of London Theater (SOLT) is preparing to lift the velvet rope on Sunday perfs.

Most London theaters play Monday through Saturday — tied to the British practice of not working Sundays. Not until 1994 were large stores allowed to open for business through the weekend.

The impetus for the general change follows close on the heels of a separate agreement specifically for Sunday openings at the National Theater, which began a three-month trial period of Sunday matinees Sept. 21. The National’s director of marketing Sarah Hunt is buoyant about the results.

“Tickets went on sale on July 23, and all Sunday performances for ‘War Horse’ have (sold out) ,” says Hunt. “And the Sunday business for the Juliette Binoche/Akram Khan dance piece “in-i” has been 92%. We’re running the trial until Jan. 18, and then we’re taking a break to take stock.”

Some shows — currently Kenneth Branagh starrer “Ivanov,” long-running tap sensation “Stomp” and Disney’s “The Lion King” — however, have negotiated separate agreements with both Equity and Bectu (Broadcasting, Entertainment, Cinematograph and Theater Union) in order to play Sundays. Providing all company members on a show are paid at least £520 ($927) per week — $214 higher than the minimum — Sunday performances are permitted.

“The terms include both a new minimum wage and new terms of agreement for Sunday openings,” Equity spokesman Martin Brown told Variety. “We’re delicately poised toward the endgame — we’re optimistic about it.”

The most successful case thus far has been “The Lion King,” which built Sunday performances into its initial London contracts. However, the production didn’t implement them until its second booking period, which began in October 2000, a year after the London premiere. Average attendance at Sunday shows has been 96% of capacity.

The National’s results are unsurprising given the org’s location on the highly popular South Bank, a stretch beside the Thames with an annual footfall of 20 million. Yet expanding to become a seven-day operation has specific consequences for a building with three auditoria and around 800 staff.

“We need to assess its impact, and see how it works out financially,” Hunt says. “At the moment, we’re only playing Sundays in the Olivier and Lyttleton auditoria. To open the Cottesloe as well would mean opening up another area of the building.

“Those additional front-of-house and security measures alone would have major cost implications,” she continues. “At some point that might be viable, but we have no immediate plans.”

The National’s negotiations, steered by executive director Nick Starr, have taken at least two years. Bectu official Willy Donaghy believes the agreements reached will have a domino effect, opening up the theater sector in the British capital to significant extra revenue. Whether London theaters eventually will follow the New York pattern of playing Sunday matinees and going dark on Mondays remains to be seen.

“Negotiations with SOLT have been highly constructive,” says Donaghy. “There are six or seven different deals for separate departments covering totally different jobs.”

Future West End negotiations with Bectu will, like those at the the National, be based on voluntary agreements by individual members. So, if Bectu and Equity members agree to the SOLT terms, how soon could new working patterns be implemented?

“We want it sooner rather than later,” Brown says.

He is not alone in recognizing the increased box office potential of Sunday perfs, especially for U.S. tourists accustomed to Sunday matinees.

“There has to be time to put any agreement into precise draft,” Brown says. “But subject to that initial agreement, the worst case scenario would be early next year.”

Adds Donaghy: “For the members, it’s a question of balancing quality time off with money. A few years back, one major West End musical wanted to play Sunday afternoons. The crew voted against it as being not worth their while. I told them they would be offered £100 extra … and suddenly everyone put their hands up.”