The Tories, meanwhile, will set out a range of measures to strengthen border security after Brexit including automated entrance and exit checks to identify individuals who have overstayed their visa.
Mr Corbyn will use a visit to a railway station to announce the plans which he says would save the average commuter more than £1,000 a year, and would represent the biggest ever reduction in rail fares.
It comes after Britain’s train companies confirmed over the weekend that they will hike prices by an average of 2.7% next year.
Children aged 16 and under would receive free rail travel under the party’s plans to re-nationalise the system, while part time workers would be guaranteed “fair” fares.
Labour estimate the policy will cost £1.5bn per year and would come from existing Department for Transport budgets, drawn from vehicle excise duty.
Mr Johnson will visit a port as the Conservatives unveil a five-point plan to strengthen border security after Brexit.
People will be counted in and out of the country as part of the proposals which would also make biometric passports a requirement and see the introduction of an American-style visa waiver scheme.
The party hopes the Electronic Travel Authorisation (ETA) would provide an enhanced ability to screen arrivals against watchlists and block those deemed to be a threat from entering the UK.
The Liberal Democrats have pledged to invest an additional £11bn over five years into transforming mental health services.
The party said it would make prescriptions for people with chronic mental health conditions available for free on the NHS among a raft of measures to improve services.
Sunday night saw the latest seven-way TV election debate hosted by ITV in which the parties clashed over the US president who arrives in the UK today ahead of a meeting of Nato leaders.
Brexit Party leader Nigel Farage warned it was a “great mistake” for British politicians to demonise Donald Trump.
Liberal Democrat leader Jo Swinson said that, while the relationship with the US was important, Mr Trump, who had spoken of sexually assaulting women, did not share British values.
“The last thing we should have done is to roll out the red carpet for a state visit,” she said.
Plaid Cymru leader Adam Price said Mr Farage was wrong to defend the US president while Scotland’s First Minister Nicola Sturgeon said Mr Johnson was trying to pursue the same “strong man” tactics of the president.
Labour’s shadow justice secretary Richard Burgon said Mr Trump and the prime minister were both politicians who had “given the green light to sexism, homophobia and racism”.
However for the Conservatives, Treasury Chief Secretary Rishi Sunak said that the relationship with the US was essential to Britain’s national security and should not be denigrated.
The Brexit Election on Sky News – the fastest results and in-depth analysis on mobile, TV and radio.
- Watch Dermot Murnaghan live from 9pm on 12 December
- See the exit poll at 10pm
- Watch KayBurley@Breakfast election special on 13 December
- Find out what happens next in All Out Politics special from 9am with Adam Boulton