Thomas Markle insists he's too old and frail to pose any threat to famed paparazzo Jeff Rayner that would necessitate a restraining order ... but Jeff says he still needs the protection because he thinks Thomas has nothing to lose.
According to docs, obtained by TMZ, Thomas is asking a judge to terminate the 2-year restraining order put in place last month ... claiming Jeff is harassing him by, among other things, claiming Jeff lied about him having a gun.
In his request, Thomas writes ... "I am no threat to anyone because I'm 78 years old" ... adding he's had "2 heart attacks, one stroke, and have a cane for walking."
Jeff fired back in his own legal docs ... saying Markle's age and poor health are the exact reasons why he's still worried -- simply put, he thinks Markle has nothing to lose because his time is running out anyway.
He points to Markle's OG threat which read, "If they tell me I've got terminal cancer, then I'll kill [Jeff] because I have nothing to lose."
As we reported, the co-owner of the news agency Coleman-Rayner got the restraining order against Thomas last month after the alleged threat was revealed in Tom Bower's book, "Revenge: Meghan, Harry and the War Between The Windsors."