Formal contract talks between Unifor and the Detroit Three automakers are set to begin Wednesday beginning with General Motors.

Talks are also set to begin with Ford and Fiat Chrysler Canada on Thursday in Toronto.

Negotiations are likely to last through to the end of the month with a focus on one company being established by September. By focusing on negotiations with one company the remaining contracts can then be modelled for all three automakers.

"These are perhaps the most important auto contract talks in a generation," said Unifor National President Jerry Dias in a release.

Dias will lead the negotiations and says that no deals will be made with any of the companies with commitments from each for investments in Canada.

Contracts with the Detroit Three companies expire at 11:59pm on September 19, putting the two sides in a legal strike/lockout position at that time.