LONDON — Retailers here are ready for a flood of Middle Eastern shoppers during the annual pre-Ramadan rush. Ramadan, the Islamic month of fasting, begins on June 18.

According to the tax-free shopping network Global Blue, spending by consumers from Middle Eastern countries in the pre-Ramadan period was up 43 percent year-on-year in 2014, and that trend is set to continue.

Saudi Arabian shoppers are forecast to lead the surge, with their spend up 28 percent year-on-year to date. They are the second-biggest international shoppers in the U.K. behind China.

The Qataris are expected to follow the Saudis, with the highest average spend-per-transaction of any international shopper group in the U.K., with 1,432 pounds, or $2,186.

According to Global Blue, the period around Ramadan is one of the most important events on the U.K. international shopper calendar, with an influx of consumers from countries including Qatar, the United Arab Emirates, Saudi Arabia and Kuwait.

Ramadan is earlier than ever this year, running from June 18 to July 17. Gordon Clark, U.K. country manager of Global Blue, said as a result, retailers and hotels are likely to benefit from a “double hit” as Middle Eastern shoppers return for post-Ramadan shopping in mid-July.

Global Blue said fashion and clothing is the “overwhelming” top purchase category for Middle Eastern shoppers, who spend an average of 931 pounds, or $1,420, per transaction.

The company added that men love to purchase high-end tailoring while women dress in the latest designer fashions for women-only parties at home.