The man held on Thursday is former London schoolboy Khalid Mohamed Omar Ali, the BBC understands.

It's been a slower day in Westminster today with Parliament not sitting before the election. 

Here is a recap of the main events of the day. 

• Paul Nuttall has said Brexit is a "job half done" as he launched his party's election campaign  
• The European Council President said an agreement on "people, money and Ireland" must come before negotiations on the EU's future relationship with the UK  
• A terror suspect arrested near the Houses of Parliament on Thursday is Khalid Mohamed Omar Ali
• The UK is urgently drawing up new laws that will enable it to continue imposing sanctions on foreign countries after Brexit

Image source, Jack Lopresti

A Conservative MP facing deselection by his own party has blamed a "vicious smear campaign" against him following revelations about his private life.

Jack Lopresti said a letter sent to party members, calling for a new candidate, was part of an "attempt to destroy my character and reputation".

The Filton and Bradley Stoke MP left his wife for fellow MP Andrea Jenkyns, who gave birth to their son in March.

Mr Lopresti said he would "love the opportunity" to remain as an MP.

Read more. 

Prime Minister Theresa May has been holding talks in London with Japanese prime minister Shinzo Abe.

Speaking at a joint press conference, Mrs May said this was not the time for the UK to "step back from the world, but rather to step up and continue to stand tall among our friends and allies".

She added that she had also updated Mr Abe on the government's plans for Brexit. 

Following on from Paul Nuttall's announcement that he will seek election, his deputy Peter Whittle has also confirmed his intention to stand. 

But just like Mr Nuttall, who has yet to announce in which seat he will stand, Mr Whittle has not confirmed which constituency he will target. 

Gerry Adams welcomes the move but Ian Paisley says it is 'fantasy politics'.

The 2017 general election campaign is still in its infancy but there have been a busy few days.

Labour's shadow chancellor, John McDonnell, has described the slowdown in economic growth as "really worrying" - and accused Theresa May of rushing to an election amid fears of a worsening economy.

The UK economy grew by 0.3% at the start of the year - the slowest growth rate since the first three months of 2016 - according to official figures.

Mr McDonnell said: "It does show you though why Theresa May has gone for this early election because the economy is now on the turn and you can see why she has rushed to an election.

"This is an unstable economy that is increasingly weak as a result of government policies."

Mr McDonnell acknowledged that Labour's credibility on the economy was yet to recover, saying: "I can understand that because Labour was in power when the crash happened and whichever government was in power when a crash happened, people lost confidence in them even though it wasn't Labour's fault."

Boris Johnson's Tory colleagues race to defuse his comments about the UK joining a US attack on Syria.

UKIP was not "going to war on Muslims" but setting an integration agenda, says its deputy leader.

Peter Whittle was speaking to Daily Politics presenter Jo Coburn about its bid to ban full face veils, and the reaction to it.

They also spoke about the number of candidates the party would field at the general election, and why it may not oppose pro-Brexit candidates from other parties.

Election candidates are turning to crowdfunding sites to raise money for the snap general election.

As well as electing local councillors in next month's local elections, six areas of England will also be choosing new kinds of local leadership - metro mayors.

They will not just just represent one city, but wider regions, as Jenny Kumah reports for the Daily Politics.

A live television debate with the leaders of the four main political parties in Scotland is to be held by STV in the run-up to the general election. 

SNP leader Nicola Sturgeon, Scottish Conservative leader Ruth Davidson, Scottish Labour leader Kezia Dugdale and Scottish Liberal Democrat leader Willie Rennie will take part in the debate on 24 May.

Chris Ruane and Gareth Thomas hope to re-capture the seats they lost to the Conservatives.

Earlier today UKIP leader Paul Nuttall launched the party's election campaign in London, setting out some of its manifesto pledges and fielding questions from journalists. 

But Channel 4's political correspondent notes some people were absent from the launch.   

Image source, @HRH_DUKE_OF_URL/TWITTER

It's the social media fail that is celebrated every year - at least on Twitter and Facebook.

Six years after it first started, people are still celebrating Ed Balls Day. 

Click here for more on what it is and the tweets people have sent to mark the day. 

Image source, PA

Brexit Secretary David Davis has played down suggestions of future British military action in Syria as "hypothetical".

Echoing comments by Prime Minister Theresa May, Mr. Davis said that there was "no option" on the table to do anything on Syria in the forseeable future. "When an option comes we'll look at it properly".

The comments follow remarks on Thursday by Foreign Secretary Boris Johnson who said that Britain would find it "difficult" to reject a request from the United States for airstrikes on the Assad regime in the event of a further chemical attack.

But Mr Davis, speaking earlier during an election campaign visit in Lancashire, sought to qualify Mr.Johnson's stance. 

"The US is an ally of ours. If they come and ask for help we'll look at it as we always do with a sympathetic eye".