In January, Meghan's lawyers presented their case, essentially claiming that the personal nature of the letter was a crucial factor. Meghan's lawyer Justin Rushbrooke QC described the 1250-word letter as "a heartfelt plea from an anguished daughter to her father".
Lawyers for the duchess also told the High Court the publication of the "intrinsically private, personal and sensitive" letter was a "triple-barrelled invasion of her privacy rights".
Rushbrooke said: "It was written, in short, by a daughter who felt she had reached a breaking point with her father."
Thomas Markle claims that the letter was not an olive branch offered with love by Meghan, but rather a strongly worded criticism. In his statement to the court in January, Thomas' statement alleged that claims made by sources close to the duchess - which appeared in an article in "People" - that the letter offered love and forgiveness was a lie.
"That suggestion was false. The letter was not an attempt at a reconciliation. It was a criticism of me," Markle's statement read.
"The letter didn't say she loved me. It did not even ask how I was. It showed no concern about the fact I had suffered a heart attack and asked no questions about my health.
"It actually signalled the end of our relationship, not a reconciliation."
Thomas Markle, a former Hollywood lighting director, only selected parts of the letter to release to the Mail on Sunday. Markle said he didn't release the whole letter at the time "because I thought the letter as a whole made Meg look terrible", his statement said.
If Meghan's plea for a summary judgement is denied, the case will go to trial in September with a high likelihood that both father and daughter will be asked to take the stand.
