The passenger of a vehicle involved in an alleged drunk driving incident that took place on Highway 20 in Quebec's Montérégie region is fighting for her life.

The incident took place around 7:30 p.m. near Sainte-Hélène-de-Bagot, about 75 kilometres east of Montreal on Saturday.

Police said the 44-year-old driver of an eastbound vehicle lost control and crossed the median of the divided highway.

Once across the median, the vehicle struck another heading in the opposite direction.

The driver was transported to hospital with minor injuries while the passenger sustained critical injuries.

The 44-year-old man was charged with impaired driving causing injuries.

These charges could change depending on the woman's health condition.

The driver of the westbound car was also treated for with minor injuries.