The doctor who clashed with Jacob Rees-Mogg over medical supplies in the event of a no-deal Brexit will take on the Conservatives in the next general election as a candidate for the Liberal Democrats.

But Dr David Nicholl has decided not to stand against Rees-Mogg, but the chancellor, Sajid Javid, in Bromsgrove in the West Midlands in an effort to expose what he believes is Brexit dishonesty.

He expected to be unveiled as the Lib Dem candidate at a meeting of local campaigners on Friday night.

The consultant neurologist said he has decided to get directly involved because of the “appalling behaviour” of the last week.

“I think the issues have got a whole lot bigger than the no-deal Brexit side of things, it is fundamentally about whether we are prepared to have any honesty in politics now.”

He faces an almost impossible task to unseat Javid.The chancellor took 62% of the vote in Bromsgrove in the 2017 election, up 8% on 2015. The Lib Dems came a poor third with fewer than 2,500 votes, a share of just 4.6%.

But Nicholl is confident he will pick up disenfranchised Tories.

“Things are completely different to 2017. I think when you have a prime minister who is prepared to mislead the Queen, you will have many people who vote Tory, not people in the Tory party, in Bromsgrove, who will be utterly appalled with what is going on and will be looking for a new home,” he said.

Nicholl joined the Lib Dems earlier this summer. He left the Labour party after Owen Smith, the shadow Northern Ireland secretary, was sacked, considering it a decision with damaging consequences for the region.

He said he thought the Lib Dems had “clearly got the best chance” to woo remain voters or disenchanted Tory voters and Labour’s decision to remain neutral on Brexit would destroy its chances in the polls.

Nicholl said he was not tempted to run against Rees-Mogg because Bromsgrove was his constituency and he would continue to work as a consultant at the Sandwell and West Birmingham NHS trust.

“I wanted to deliberately draw attention to Sajid Javid’s poor judgment for appointing Matthew Elliott [the Vote Leave chief executive] as his campaign manager during the [Conservative] leadership election,” he said describing Elliott as “part of the problem”.

Nicholl clashed with Rees-Mogg in early September over contingency plans for a no-deal Brexit he had drawn up for the government for epilepsy and neurology drugs.

Rees-Mogg accused Nicholl of fearmongering and told him he “should be quite ashamed” to “try to spread fear across the country” over potential shortages of medicine caused by a no-deal Brexit.

Q&A What does a no-deal or WTO-rules Brexit mean? Show If the UK leaves the EU without a deal it would by default, become a “third country”, with no overarching post-Brexit plan in place and no transition period. The UK would no longer be paying into the EU budget, nor would it hand over the £39bn divorce payment. The UK would drop out of countless arrangements, pacts and treaties, covering everything from tariffs to the movement of people, foodstuffs, other goods and data, to numerous specific deals on things such as aviation, and policing and security. Without an overall withdrawal agreement each element would need to be agreed. In the immediate aftermath, without a deal the UK would trade with the EU on the default terms of the World Trade Organization (WTO), including tariffs on agricultural goods. The UK government has already indicated that it will set low or no tariffs on goods coming into the country. This would lower the price of imports – making it harder for British manufacturers to compete with foreign goods. If the UK sets the tariffs to zero on goods coming in from the EU, under WTO “most favoured nation” rules it must also offer the same zero tariffs to other countries.

WTO rules only cover goods – they do not apply to financial services, a significant part of the UK’s economy. Trading under WTO rules will also require border checks, which could cause delays at ports, and a severe challenge to the peace process in Ireland without alternative arrangements in place to avoid a hard border.

Some no-deal supporters have claimed that the UK can use article XXIV of the General Agreement on Tariffs and Trade (Gatt) to force the EU to accept a period of up to 10 years where there are no tariffs while a free trade agreement is negotiated. However, the UK cannot invoke article XXIV unilaterally – the EU would have to agree to it. In previous cases where the article has been used, the two sides had a deal in place, and it has never been used to replicate something of the scale and complexity of the EU and the UK’s trading relationship. The director general of the WTO, Roberto Azevêdo, has told Prospect magazine that “in simple factual terms in this scenario, you could expect to see the application of tariffs between the UK and EU where currently there are none”. Until some agreements are in place, a no-deal scenario will place extra overheads on UK businesses – eg the current government advice is that all drivers, including lorries and commercial vehicles, will require extra documentation to be able to drive in Europeif there is no deal. Those arguing for a “managed” no deal envisage that a range of smaller, sector-by-sector, bilateral agreements could be quickly put into place as mutual self-interest between the UK and EU to avoid introducing or to rapidly remove this kind of bureaucracy. Martin Belam

Nicholl told him that he drew up the Operation Yellowhammer plans for his area of expertise. The report outlined the probable consequences of the UK leaving the EU without a deal. He said he had blown the whistle on the plans because he felt they were unsafe.

Days later Rees-Mogg, now leader of the House of Commons, was forced to apologise to him after comparing him to the disgraced anti-vaccine doctor Andrew Wakefield, prompting a backlash from the medical profession, including criticism from England’s chief medical officer Dame Sally Davies.

This prompted Nicholl to abandon work and join the protests outside parliament, commandeering anti-Brexiter Steve Bray’s megaphone to accuse Rees-Mogg of using parliamentary privilege to attack whistleblowers.

In other news, Dr David Nicholl has taken to College Green with a message for Jacob-Rees Mogg...asks him to repeat his earlier comments outside the House of Commons, and if he does, Nicholl says “I will sue” pic.twitter.com/O9gZM69jqp — ollie cole (@ProducerOllie) September 5, 2019

Nicholl said he would “certainly hope to get a lot of the remain” votes in Bromsgrove and would rely on a 14-year campaign on the “rule of law” to “bring the fight to Sajid Javid”.

Nicholl campaigned for more than a decade to help free Shaker Aamer from the US camp in Cuba and he was finally released without charge in autumn 2015.