And what of the Liberal Democrat’s long-term ambition to change the voting system to a form of proportional representation?

"Would it be fairer if Nigel Farage, and Nigel Farage’s party, got many more seats, given that in the past he’s had millions of votes, this election he’s likely to get millions of votes, is that the change you are prepared to see?" Robinson asks.

He’s then asked about the party’s youth mobility scheme - which would allow people under the age of 35 in the EU come to the UK on a three-year work visa.

Davey says there is already a scheme in place for countries like Australia and South Korea, and this scheme is a "capped system" and not equivalent to the free movement of labour.

It is "sensible and means you can control things", but also means“ our young people have that wonderful freedom”, he says.

Davey says he does not believe joining the single market with the free movement of labour will happen in the next Parliament, but argues he believes a good trade deal is possible if the Lib Dems’ approach is taken.

He says he has been assured by politicians on the continent that a better trade deal is possible without increased immigration to the UK - which he says needs to come down.

And what about Brexit? Robinson asks, pointing out that the 'B-word' is not mentioned until page 112 in the Lib Dems’ manifesto. At the last general election in 2019, the party stood on a pro-remain platform with a pledge to revoke Brexit without a second referendum if the party won a majority.

"Are you prepared to make enemies and pay the price of freedom of movement of people for a better trading relationship with the EU?" Robinson asks.

But Robinson challenges the Lib Dem leader on this, putting to him that the party has blocked development in areas it runs.

Robinson says the Lib Dems have blocked plans for a new town with 3,000 homes near Henley, and the party’s deputy leader Daisy Cooper opposed plans for thousands of new homes built near her St Albans’ constituency in Hertfordshire.

Davey says for every example like that there are others which prove his case - including in Kingston, where his wife is the housing portfolio leader. "We have the largest council house building programme in 40 years," he says.

Attention now turns to the economy - one of the key battlegrounds of this election campaign.

Robinson asks Davey whether he agrees with Labour leader Keir Starmer who said he was prepared to “make enemies” in order to get the economy moving, including by reforming the planning system.

Davey says the current planning system is not delivering the “homes we need, and it’s not doing it at pace, and it’s frankly doing it to the developers’ tune”.

He says a “community-led approach” is needed - meaning homes are built in areas the community needs, are more affordable and crucially has the infrastructure in place to support development.

Returning now to the NHS, Robinson asks where the money will come from to pay for pay increases for junior doctors and nurses, or the long-term NHS workforce plan the party is committed to.

Davey says that people working across the NHS will realise if they return Lib Dem MPs they will get politicians who take their concerns seriously.

He claims the party’s manifesto is "super cautious", with low estimates on the amount of tax revenue they will raise if their policies are enacted.

Robinson challenges him on this, citing analysis from the think tank the Institute for Fiscal Studies which explains that taxes on business will be felt by ordinary people, whether it’s through increased bills, a cut to dividends to shareholders or a squeeze on pay for workers.

Davey disagrees, and says the Lib Dems will not increase personal taxes for ordinary people because they’re at "record levels" under the Conservative government.

The interview moves on to the Liberal Democrat manifesto (the key details of which you can read here).

Robinson puts it to Davey that it is not credible, as his manifesto outlines, that increased spending on public services will be funded by just taxing “the bad guys” - banks, water companies, and tech giants.

Davey says banks are making record profits and can pay more, while oil and gas companies have made huge profits off the back of Putin’s war in Ukraine.

Robinson challenges Davey, asking whether he believed the establishment over “the little guy”.

But Davey pushes back and argues there was a “conspiracy of lies” in this scandal, as seen with others.

He says the Lib Dems are pushing for a new law which requires public officials to have a duty of candour - meaning they will face the courts if they don’t tell the truth and are found out - and stronger protection for whistle-blowers "so the little guy gets that support".

Davey says he took Alan Bates’s concerns "very seriously" and took the issues he raised to his officials and the Post Office.

He insists he was given "categorical assurances" that independent IT specialists had checked the Horizon system and assured him it was working "incredibly well in other areas".

Robinson now moves on to talk about the Post Office Horizon scandal (more on that here.)

For context: Davey’s brief as consumer affairs minister in the coalition government between 2010 and 2012 included overseeing the Post Office, and he will be giving evidence to the ongoing inquiry later.

Robinson references a meeting he had with campaigner Alan Bates who alerted him to the huge miscarriage of justice.

"Why weren’t you on his side? Why were you on the side of the establishment, to the Post Office?"

Davey says the issue of student fees was the most difficult one to take – one he and his party were punished for.

He says he learned two lessons from that – one, not to promise something you can’t deliver, and two, the need to rebuild trust.

He argues the Lib Dems have shown through their strong recent election performances during this Parliament.

Robinson now turns to the matter of student fees. For context, the Lib Dems pledged to oppose increases in tuition fees before the 2010 election, but were part of a government which saw fees triple.

“If there’s somebody watching now who’s angry about austerity and angry about the level of student fees, why should they trust Ed Davey?” Robinson asks.

Robinson challenges his record, putting to him that he worked with the Tories to deliver austerity, including £27bn worth of cuts to the welfare budget during the coalition years.

Davey maintains that there were things the Lib Dems fought against – like the freeze to benefits and pensions when inflation was at 5.2% - and won.

"I am not proud of every decision I had to take, but my point is if you wanted to change things, you had to roll up your sleeves and not quit."

Davey argues that the Lib Dems in government made “tough decisions”.

"I had a choice, as did every Liberal Democrat Minister - did I stay there or did I go?" he says.

He insists the Lib Dems "rolled up our sleeves" and fought for things they believed in, stopping the Conservative Party from going further with cuts.

Robinson now turns to Davey’s time as a minister during the coalition government with the Conservatives between 2010 and 2015 – a government, Robinson points out, which delivered huge cuts to public services.

"You’ve never criticised austerity, why not?"

Davey says his party stands for a "fair deal" – with the health service and care at the heart of it. He talks of his own experiences as a carer for his elderly relatives and his son, John, who has a condition meaning he can’t walk or talk.

"But how will you save the NHS without power?" Robinson pushes back.

By "winning the argument" and making sure we get lots of Lib Dem MPs who will champion their local health service, Davey insists.

Robinson begins by referencing Davey’s "rollercoaster" time in politics – one minute in government, then losing his seat in 2015 and seeing his party almost "wiped out". And now on the up again.

"If you do get power, what will you do?"

Lib Dem leader Ed Davey is seated and ready to face questions from the BBC's Nick Robinson, in the last in the series of leaders interviews on Panorama.

We'll be sharing the key lines here. You can follow along by pressing the WATCH LIVE button at the top of this page.