His speech, shared with UK media, will coincide with the release of the cabinet’s technical notes outlining the country’s approach to minimizing the Brexit impact, according to the ITV news channel.
The notes will be published in batches from Thursday through September. The first issue will advise businesses and the public on how to get ready for the worst-case scenario.
Raab will insist he believes that "a good deal is within our sights" as he rules out triggering a tit-for-tat with Brussels by introducing new border checks or travel restrictions.
"If the EU responds with the level of ambition and pragmatism, we will strike a strong deal that benefits both sides. But, we must be ready to consider the alternative," he will say.
Time is running out for British and European negotiators to strike a deal on the Northern Irish border and the future EU-UK relationship by the end of October. The United Kingdom is set to withdraw from the union on March 29, 2019.