Sergio Rojas and Linda Martinez pleaded with the Immigration Department to let them remain in the country on compassionate grounds because of their three-year-old son Jonathan's medical condition.
But MP Ryan Leef says a letter to the family from the Yukon Child Development Centre had been changed and embellished.
The family has said their son's skull deformation and neck muscle disorder means he needs daily attention and care not available in Mexico.
But the parents exaggerated the urgency and extent of Jonathan’s treatment and changed signatures on the letter, Leef said.
He called the alterations a betrayal and said he would step back from the case.
"They, in fact, didn't just embellish," Leef said. "They added lines about the quality of care ... for what Mexico could provide."
He said the parents implied that Canada is the only place that could provide the needed care, "if in fact any of this were needed at all."
Manipulating the immigration process is unfair and means he will be reluctant in the future to advocate for people who may truly be in need, Leef said. (Whitehorse Star)