Theresa May and Jeremy Corbyn will square off at Prime Minister's Questions for the last time before the General Election and possibly ever.
On Wednesday, the Prime Minister and Labour leader are expected to use the final House of Commons set-piece before the June 8 poll to push their main campaign messages.
Mrs May is likely to stress that only she will provide the "strong and stable leadership" required in Brexit negotiations and call on voters to give her a mandate for those talks, while attacking Mr Corbyn's "chaotic" leadership.
The Opposition leader is likely to try and widen the debate as he seeks to gain cut-through with the public for Labour's policies to tackle inequality and the "rigged system" he says is propped up by the Tories.
It could be the last time the pair ever debate head-to-head given that Mr Corbyn is highly likely to face calls to resign or a leadership challenge if Labour loses the election.
Mrs May is sure to face similar calls if the Tories lose, given their huge leads in opinion polls and widespread predictions of a landslide victory.
The PM is also refusing to take part in TV debates and Mr Corbyn could raise a BMG Research poll for the Independent which shows that 54% of Britons want her to take part in head-to-head contests during the campaign, while just 25% said they did not.
Mrs May faced taunts that she was "frit" during last week's PMQs and Mr Corbyn could seek to exploit what is likely to be raucous atmosphere in the Commons.
Elsewhere, Labour will make the NHS the focus of their day of campaigning, with shadow health secretary Jonathan Ashworth set to promise to lift the 1% cap on pay rises for "undervalued" health service workers.
At the Unison health conference in Liverpool, Mr Ashworth will also pledge to reinstate funding and support for students of health-related degrees and put forward policies to tighten up rules on safe staffing levels.
Liberal Democrat leader Tim Farron will urge businesses to "dump the Tories" because they would be "funding their own funeral" if they donate to a party that backs leaving the European single market.
At the National Pharmacy Association in Tory-held St Albans, he will say: "With this disastrous hard Brexit the Government is hurting businesses, both big and small, costing jobs and hitting families.
"All this means fewer jobs, higher prices and spiralling costs of things like fuel. This is a Brexit squeeze affecting millions of people."