Tory leadership contender Jeremy Hunt is to outline his plans for a no-deal Brexit, including a £6bn pledge to the fishing and farming industries.
Setting out what he would do as PM, Mr Hunt will say farmers and fishermen “face uncertainty” if there is no deal, but that he will “help smooth it over”.
Some farming leaders have warned against leaving the EU without a deal.
Mr Johnson also promised to support the rural community after Brexit during a meeting with farmers last week.
Mr Johnson and Foreign Secretary Mr Hunt are competing against each other to become the next Conservative leader.
The Conservative Party’s 160,000 members will begin voting next week and Theresa May’s successor is expected to be announced on 23 July.
In a speech in London on Monday, Mr Hunt will say the food and agriculture industry deserves to be treated in a similar way to the financial services industry in 2008, when banks received a multi-billion pound bailout by the government.
He will promise to create a temporary “no deal relief programme” for the fishing and farming industry who export to Europe – aimed to be similar to US President Donald Trump’s promise of £16bn for farmers affected by Chinese tariffs.
He will also promise to set up a no-deal committee, with similar powers to Cobra, to make sure the government is ready to leave by 31 October, as well as a transport committee to keep goods moving through ports and airports.
“If you’re a sheep farmer in Shropshire or a fishermen in Peterhead I have a simple message for you,” Mr Hunt is expected to say, “I know you face uncertainty if we have to leave the EU without a deal.
“I will mitigate the impact of a no-deal Brexit on you and step in to help smooth those short term difficulties.
“If we could do it for the bankers in the financial crisis, we can do it for our fisherman, farmers and small businesses now.”
If the UK leaves the EU without a deal, it will automatically trade under the basic World Trade Organization (WTO) rules.
Under these rules, the tariffs – the taxes on imported and exported goods – will be different to what the UK currently trades under, which means the cost to farmers to export products could change or they could be affected by competition from abroad.
The government has already announced its plans for tariffs in the event of a no-deal Brexit.
A temporary scheme will see some tariffs protect farmers producing meat, while other sectors of farming will have low or no tariffs.
Farming unions have previously warned against a no-deal Brexit, citing the impact of tariffs on agri-exports as a threat, and the National Farmers Union has said British farming will be “damaged” if it happens.
When challenged last week about the potential impact leaving the EU without a deal would have on farming exports, Mr Johnson told farmers in Cumbria he did want such an outcome and intended to negotiate a tariff free area with Europe.
He added that farmers “should be assured that we will support the rural community, with price support, efficiency payments, whatever”.
On Sunday, Mr Hunt said he would be prepared to pursue a no-deal Brexit “with a heavy heart”.
Mr Johnson has previously said the UK must leave on 31 October “deal or no deal” and that he would take the UK out of the EU by Halloween “come what may, do or die”.
He challenged Mr Hunt to make the same commitment.
In an interview with Sky’s Sophy Ridge on Sunday, Mr Johnson reiterated the commitment, saying he would take “personal responsibility” for ensuring the UK leaves by 31 October, with or without a deal, as the current “drift and dither” could not continue.
Asked whether he was willing to suspend Parliament to force through a no-deal exit, he said he did not “like the idea” but MPs must accept “responsibility” given the grave situation.
Mr Johnson also said he was still committed, whatever the Brexit outcome, to cutting corporation tax from its current rate of 19% to 12.5%.
Meanwhile, he has continued to refuse to face Mr Hunt in a head-to-head debate before ballot papers are sent out to the Tory membership.
A Sky News debate was planned for Monday but will now see Mr Hunt interviewed by Kay Burley.
Mr Johnson has previously said he believes he is doing enough head-to-head debates with Mr Hunt.