The Daily Mail article questioned why Eugenie's wedding was drawing so many similarities to Prince Harry and Meghan Markle's nuptials held in May, and asked why Eugenie was being granted such a lavish affair considering she is so much further down the line for the British throne.
Harry is sixth in line, while Eugenie is ninth.
At one point, the article dismisses Eugenie as 'constitutionally important as one of the Queen’s corgis.'
Wade's scathing letter continues, 'The rhetoric is inflammatory and divisive, suggesting that the Princess has a ‘hunger for glitz and glamour that is every bit as monstrous as Mother’s Fergie’s’ and making the ill-search judgement that the Princess has done ‘almost nothing of note.’
'I would like to raise into question whether Jan Moir has ever met or spent time with Princess Eugenie or whether the source of her malicious contempt for a 28-year-old woman is the result of years of unfounded and hurtful abuse that has been directed towards the Princess and her family.'
Wade concludes, 'It is imperative that we support freedom of expression, but not when the intended outcome is to inflict pain on another person or incite others to do so.'
Eugenie and Jack will wed on October 12 at St George's Chapel in Windsor. The couple will follow the ceremony with a carriage ride through the streets of Windsor and back into the castle. Like Harry and Meghan, the future newlyweds are also inviting 1200 members of the public to enjoy their special day.
Representatives from the princesses most favoured charities will also be in attendance, as was at Harry and Meghan's wedding.
Related: Princess Eugenie accused of 'copying' Meghan Markle