The independent fact-checking charity Full Fact has examined claims made in the party's manifesto.
In his launch speech, Jeremy Corbyn said Boris Johnson’s claim that he will get Brexit done was "a fraud on the British people".
It’s not fraudulent of Boris Johnson to say his deal gets Brexit done. If approved by parliament, his withdrawal agreement - which is what he refers to as his "oven-ready" deal—would mean that the UK stops being a member of the EU.
But Jeremy Corbyn is right to point out that the Brexit process will continue for many years. Mr Johnson’s withdrawal agreement wouldn’t secure a trade deal with the EU.
The UK would enter a "transition period" during which we would still follow EU rules and pay money to the EU. This is set to run until the end of 2020 but could be extended by either one year or two.
At the end of the transition period, the UK could either start trading with the EU under the terms of a newly-negotiated trade deal, or start trading with the EU on WTO or no-deal terms.
Mr Corbyn also cited EU chief Brexit negotiator Michel Barnier as saying a UK-EU Brexit deal would take three years to negotiate.
Michel Barnier’s quote needs to be understood in context.
Last month, he said of a future trade deal: "We will have to renegotiate for one year, two years, three years, maybe more in some areas, to rebuild all that will have been pulled apart by the desire of those backing Brexit."
So he was not totally definitive, and the phrase "in some areas" is important.
Nonetheless, experts say extending the transition period beyond 2020 "may prove unavoidable".
It’s also worth noting that none of the EU’s other recent free trade agreements have been negotiated and provisionally implemented in under three years. One difference in this case is that Boris Johnson’s government and the EU have already agreed some broad principles for what a future deal should look like.
The EU’s track record brings us on to the question of how long a UK trade deal with the USA would take. Jeremy Corbyn says it would take "even longer" than three years, and he has previously pointed to the EU-Canada trade deal as an example.
That dealtook five years to negotiate, and another two before it was provisionally applied. That doesn’t mean a UK-US trade deal necessarily would take as long. We’ve not seen any robust predictions for how long a UK-US deal would take, and we don’t yet know exactly what would be on the table during discussions.
Some major EU trade deals (for example with South Korea and Ukraine) have taken longer than seven years to provisionally implement, while others have been quicker than that.
The manifesto also claimed that "energy use in buildings accounts for 56% of the UK’s total emissions, making it the single most polluting sector".
This doesn’t seem quite right.
Transport is the single biggest sector for emissions in the UK at 27%.
We’ve seen Labour make a similar claim before, that "electricity and heat use in buildings, when taken together represent 56% of the UK total" of emissions. This seems to come from government breakdowns on which sectors released the most greenhouse gas emissions in 2017.
It looks like Labour added together the emissions that come from the energy supply sector (24%), business (17%) and residential (15%) sectors, to get 56% of total emissions.
But it’s unclear how this relates to ‘buildings’ as Labour claims and we’re going to look into this further.
Jeremy Corbyn also said Labour’s manifesto was costed with:
"No increases in VAT or income tax or National Insurance for anyone earning less than £80,000.
"There is no increases for 95% of taxpayers."
It’s correct that the Labour manifesto plans no increases in VAT, income tax or National Insurance for people earning less than £80,000.
It’s also correct that people earning less than £80,000 account for around 95% of taxpayers - somewhere between 95% and 96% according to 2016/17 figures from HMRC.
But that doesn’t mean Labour plans no tax rises whatsoever for these people, because there’s more to tax than just VAT, income tax and National Insurance.
For example Labour’s manifesto commits to scrapping marriage allowance, a policy introduced in 2015 which gives a tax break to couples with a combined income of under £62,500.
In 2018/19, 1.78 million people claimed marriage allowance at a cost of £485 million.
Apart from that there are various other taxes that could affect people with salaries of under £80,000.