Facebook have finally released a string of pro-Brexit adverts that popped up on voters’ feeds before the EU referendum in June 2016.

The Digital, Culture, Media and Sport Committee released scores of ads from the official Brexit campaign group Vote Leave, another group called BeLeave, and Northern Ireland’s Democratic Unionist Party.

Earlier this month, the Electoral Commission fined Vote Leave and Darren Grimes from BeLeave, and reported them to the police for breaking election law by co-ordinating with each other. They deny the accusation.

The ads were commissioned from the Canadian data firm AggregateIQ and were targeted at specific groups of people, making them hard for journalists to track at the time.

For the first time, we can see what kind of messages Vote Leave and others were targeting at key voters in a referendum campaign dominated by false statements and half-truths.

Some of the claims – like the prospect of an extra £350m to spend on the NHS – will be familiar to readers. We and others have already FactChecked them to death.

But some of the ads featured claims that hadn’t been widely circulated elsewhere. If FactCheck had been able to see these ads at the time, what would we have said?

5.23 million more migrants moving to the UK

We can’t find a source for this claim, but reports from the time suggest that Vote Leave thought this was the likely number of people who would immigrate to Britain from aspiring EU member states Turkey, Albania, Montenegro, Macedonia and Serbia.

There are three problems with this claim. First, it was obvious at the time that imminent EU membership for Turkey – by far the most populous of those countries – was far from a done deal, thanks to concerns about political instability and human rights.

Second, Vote Leave’s source appears to be their own internal modelling, which makes it impossible for us to FactCheck the methodology.

Lastly, remarks like this only make sense if voters were choosing to leave the EEA as well as the EU. This is the only way Britain could pull out of freedom of movement rules and stop immigration from new EU member states.

But there was no guarantee at the time that a Leave vote was a vote to end freedom of movement.

FactCheck verdict: many of the claims in these ads hinge on threats of large-scale immigration from new member states. But the chances of Turkey getting EU membership were always unlikely, and in any event, a Leave vote did not guarantee an end to freedom of movement rules.

Whaling

This is one of a number of ads about whales – others feature graphic images of dead animals.

The text that accompanies this image says: “The EU is supporting commercial whaling by forcing us to allow ships carrying whale meat to dock at our ports!”

There is an element of truth to this, but the accusation that “the EU is supporting commercial whaling” is highly questionable.

In fact, the EU bans whaling and importing whale products for all member states. None of the European territories that still hunt whales – Iceland, Norway, Greenland and the Faroe Islands – are full members of the EU.

The bloc also lobbies other governments like Japan and Norway to encourage them to ban whaling.

However, it is possible for whale products to transit through EU ports to non-EU destinations, and the European Commission doesn’t appear to be keen to close this loophole.

So you could conceivably argue that the UK would be in a better position outside the EU to enact a unilateral ban on whale meat coming through British ports.

But some anti-whaling campaigners are lukewarm on this option, pointing out that it would be tricky to change the law and would probably have no effect on the whaling industry.

FactCheck verdict: it’s too simplistic to say that the EU supports commercial whaling. The EU has been a force against whaling, but it is true to say that whale meat can pass through EU ports.

“Now the EU wants to ban kettles!”

Yes, the EU introduced legislation calling for manufacturers to make kettles more energy-efficient.

No, this did not represent a blanket ban on kettles.

FactCheck verdict: nonsense

Polar bears

Animal rights is a recurring theme here. Other ads feature polar bears. The text for this one reads: “If we stay in the EU, we will be powerless to increase protection for polar bears.”

Again, there is a kernel of truth to the idea that the EU may have let down polar bears.

In 2013 the EU abstained on an American proposal to ban the export of polar bear products at the CITES wildlife summit.

The politics of the polar bear ban was complicated, but some wildlife campaigners felt the EU should have done more.

You could argue that an independent Britain might have voted in favour of a ban in 2013, rather than being obliged to abstain along with most other EU countries under the bloc’s complex voting rules.

But there’s little evidence of British governments ever taking a strong interest on the polar bear issue, and a single extra vote from an independent UK would have made no difference to the outcome last time.

FactCheck verdict: It’s possible to argue that Britain could take a stronger public stand on this issue outside the EU, but it’s hard to see how voting Leave would make a real difference to polar bears.

Flood defences

There are lots of ads here referencing flooding from storms Desmond, Eva and Frank.

The suggestion is that the government could be spending money from our EU membership on better flood defences. There are two problems here.

The first is that Britain actually gets money from the EU for flooding.

It was widely reported that the government had bid for cash from the EU’s solidarity fund just months before this ad was put online. EU money has also been awarded to local authorities for flood schemes.

The bigger problem is the notion that Britain would be better off economically overall after leaving the EU – that the benefit of not paying the membership fee would outweigh the costs.

This was hotly disputed during the campaign, with the Treasury, the Bank of England, the OECD, NIESR, the London School of Economics, the IMF and others all predicting that Brexit would weaken the public finances, leaving less money to spend on flood defences or anything else.

FactCheck verdict: It seems a bit unfair not to mention EU money for flood victims here. More importantly, the idea that Brexit would boost the public finances was and is highly disputed.

Jeremy Corbyn was against the EU

Vote Leave rather cheekily used Jeremy Corbyn – officially a Remain campaigner – in its ads.

The text alongside this ad quotes the Labour leader as saying: “The EU takes away from national parliaments the power to set economic policy and hands it over to an unelected set of bankers…”

Then it states: “Corbyn has a long history of opposing the EU.”

The quote is accurate. It’s from a Commons speech that Mr Corbyn made against the Maastricht Treaty – the legislation that created the EU – in 1993.

It’s also fair to say that Mr Corbyn’s history of Euroscepticism is a matter of public record. He has admitted that he voted for Britain to leave the European Communities in 1975. He voted against the Maastricht Treaty in 1993, voted against the Lisbon Treaty in 2008, and defied the Labour whip to vote for an EU referendum in 2011.

But by the time of the referendum campaign, the Labour leader had publicly backed the Remain campaign and made speeches acknowledging his previous criticism of Brussels but calling for voters to stay in the bloc.

If this ad popped up on your Facebook feed and you hadn’t been paying attention to the news, you might have missed this important fact.

FactCheck verdict: Jeremy Corbyn does have a history of euroscepticism, but campaigned for Remain in the referendum. Voters could have been misled by this ad.