The Queen's granddaughter has invited representatives from the Royal National Orthopaedic Hospital NHS Trust to attend her wedding to Jack Brooksbank on Friday.
But a spokeswoman for the council said that in terms of crowd numbers and associated stewarding and policing costs, it expected Harry's and Eugenie's nuptials to be "two very different weddings on two very different scales".
"Clearly, a line has been crossed today", opposition Labour lawmaker Emma Dent Coad wrote in the Mirror newspaper, saying even usually pro-monarchist papers had criticized the public funding of the wedding "of a minor member of the royal family".
The bride's parents left the chapel together smiling as the newlyweds embarked on a horse-drawn carriage ride through parts of Windsor.
Because the wedding takes place on a weekday, and they are "minor" royals, it is unlikely to attract the 13 million United Kingdom audience of her cousin's wedding.
Italian singer Andrea Bocelli will perform at the ceremony and so will musicians from the Royal Philharmonic Orchestra.
Kate chats to Prince Harry and Meghan. Eugenie's father, Prince Andrew, is a patron of the Royal Philharmonic Orchestra.
"It's nerve-wracking and a bit scary and all the things that come with getting married, but at the end of the day you get to marry the person you love, " she said.
The gown's low back was purposefully created to show off Eugenie's scar from her childhood spinal surgery, while its jacquard fabric included a motif of Scottish thistle, Irish shamrocks, the York rose and ivy to represent the bride and groom's families and home.
About 38,000 people signed a petition, organised by campaign group Republic, against taxpayers' money being spent on the occasion.