Royal aides are said to have held a series of top level crisis meetings over Thomas Markle Snr's "out of control" behaviour.
Palace sources claim the royal family's patience has "snapped" over his public outbursts, while one commentator has suggested the Queen may be forced to intervene to prevent further damage.
According to the Daily Mail, the Duchess of Sussex's father has repeatedly complained about being "cut off" by his daughter in media interviews with insiders saying she is at her "wits' end".
And one insider told the Mirror that Meghan is "deeply hurt" by what is becoming an "increasingly desperate situation".
They said three options were currently on the table to deal with the "precarious" situation: Meghan contacting her father directly, arranging for an intermediary to meet with him, or for the Duchess to "cut him off completely in the hope he will stop".