Elfyn Evans will make his World Rally Car debut in Sardinia this week.
The Welshman will stand in for Nasser Al-Attiyah, for whom a business meeting ruled out the possibility of making the trip to Olbia.
M-Sport had initially been granted a waiver to switch Al-Attiyah's car from a World to a Regional Rally Car, which would have allowed Evans to score points in the WRC 2 category.
That waiver was overruled however, leaving Evans with his WRC debut. He will be co-driven by Giovanni Bernacchini (Al-Attiyah's regular navigator) as regulations state only one element of the entry can be changed at this stage.
Evans vowed to take a sensible approach to competing in a World Rally Car for the first time.
He has tested Fiesta RS WRCs regularly during his time working with M-Sport and was shaking down the Sardinia cars at Kirkbride airfield in Cumbria last week when M-Sport managing director Malcolm Wilson told him one of those Fiestas was his.
"I couldn't believe it," said Evans. "When he told me I was so shocked.
"I have to say a massive thanks to Nasser and to Malcolm for this chance. It's incredible.
"I'm not going to do anything silly, just go there for experience. I've never done this rally before, so it's going to be a steep learning curve."
It is 17 years since Evans' father Gwyndaf last drove a factory Ford at the highest level, when he retired a Group A Ford Escort Cosworth from the Indonesia Rally in 1996.