Image source, PA Media

Alliance leader Naomi Long voted in East Belfast, accompanied by her husband, Michael.

Image source, PA Media

Northern Ireland's Ulster Unionist leader Steve Aiken voted in East Antrim. He was joined by his wife Beth.

The #dogsatpollingstations hashtag has been trending on Twitter today and welfare charity, The Dog's Trust, has issued some advice for owners taking their pets to polling stations.

• Most dogs - except assistance dogs - aren’t allowed into the polling station. Rather than leaving your dog tied up outside or in the car, the charity recommends taking a voting buddy to look after your pet while you vote.
• Ask your local Polling Station to have a water bowl for your dog, or take one with you.
• If you are voting in the dark, the charity suggests using a reflective collar and lead or a high visibility coat or flashing collar to make sure other voters and particularly drivers can see your pooch – especially if you live in a rural area.

The BBC is providing special election coverage on smart speakers for the first time.

Wake your device at any time throughout election night and say “give me BBC News” for an interactive bulletin with the latest results, reaction and analysis.

Read more about how to get BBC News on your smart speaker here.

Image source, Nick Triggle

It's not just members of the public taking their pooches to the polls.

BBC health correspondent Nick Triggle has taken his dogs, Pip (right) and Annie (left) to a polling station in Purley, in Croydon, London.

Esyllt Sears' dog Tym sported a festive Christmas hat as he went to a polling station in the Vale of Glamorgan.

Singer Nerina Pallot was accompanied by her dog, Maggie - complete with Christmas sweater - as she cast her vote.

• The UK is going to the polls for the country's third general election in less than five years.
• Polling stations in 650 constituencies across England, Wales, Scotland and Northern Ireland opened at 07:00 GMT.
• Prime Minister Boris Johnson, Labour leader Jeremy Corbyn, Liberal Democrats leader Jo Swinson, SNP leader Nicola Sturgeon and DUP leader Arlene Foster have all been photographed as they headed to vote this morning.
• The hashtag #dogsatpollingstations has been trending as social media users share pictures of their "pawlitical" companions.

• The first results usually come in about an hour after the close of the polls at 22:00 GMT. The rest of the results are declared throughout the night and into the next day. Most counts will be completed by 06:00 GMT.
• The BBC News website will have results for every constituency as they are announced, with a postcode search, interactive map and scoreboards. Our politics live page will have minute-by-minute updates in text and video, as well as expert analysis as the night unfolds.
• On TV, the BBC's Election 2019 results programme will be led by Huw Edwards on BBC One, the BBC News Channel, and BBC iPlayer. The programme begins at 21:55 GMT on Thursday and runs until 09:00 GMT on Friday.
• On BBC Radio 4, James Naughtie and Emma Barnett will present coverage from 21:45 GMT on Thursday.
• You can find out who is standing in your area here and compare the party manifestos here.

There are some 50,000 polling places across the UK - and we mentioned earlier that some are set up in rather unusual venues. Here's a selection:

Image source, PA Media

Image source, Getty Images

Image source, PA Media

The BBC, like other broadcasters, isn't allowed to report details of campaigning or election issues while the polls are open.

The BBC is required by electoral law to adopt a code of practice, ensuring fairness between candidates and that is particularly important on polling day.

On polling day specifically, the BBC doesn't report on any of the election campaigns from 00:30 GMT until polls close at 22:00 GMT on TV, radio or bbc.co.uk or on social media and other channels.

However, online sites do not have to remove archived reports, including, for instance, programmes on iPlayer. The lists of candidates in each constituency and the guide to parties' policies remain available online during polling day.

Coverage of what is happening on the day is usually restricted to uncontroversial factual accounts, such as the appearance of politicians at polling stations, or the weather.

Read the full article bout how the BBC reports on polling day here.

Chelsea Pensioners - the faces of the UK's veteran community - have gone out to vote in Chelsea, London.

Image source, Rick Findler/PA Wire

Image source, Rick Findler/PA Wire

Image source, Rick Findler/PA Wire

The BBC News website will feature a full breakdown of the results across the UK as they come in - via an interactive map and postcode search.

You can also follow the latest developments in your own constituency on BBC live pages and scoreboards.

Keep an eye on the @BBCElection , externalTwitter page, which will tweet out every constituency result.

Huw Edwards will be the lead presenter of BBC One's election night special, while Jim Naughtie and Emma Barnett will host live election night coverage on BBC Radio 4 through until Friday morning.

Image source, PA Media

DUP leader Arlene Foster casts her vote at a polling station in Enniskillen, in Northern Ireland.

If none of the parties get a majority, we'll be faced with a hung Parliament. In that case, as the prime minister in power before the general election, Boris Johnson will stay in office and be given the first chance to form a government.

He'll have a few options:

• Forming a coalition government - forming a partnership with another party.
• Making a confidence and supply agreement - asking for occasional help from another party.
• Establishing a minority government - where the party doesn't have a majority in the Commons but governs anyway.

If the previous prime minister fails to form either a coalition or an agreement with another party, they are usually expected to resign. They will recommend that the leader of the largest opposition party gets the chance to form a government.

If the opposition party also fails, then Parliament will be dissolved again and there will be another election.

You can find out more about what could happen here.

A burst water main has flooded a key path to a polling station in Bermondsey, South East London, preventing some voters getting in.

The polling station is situated in the Bermondsey and Old Southwark parliamentary constituency. The water main burst on the junction of Jamaica Road and Southwark Park Road.

Hannah Tookey, who waded through the water to cast her vote, tweeted: "It was too deep to wade through the middle, even in wellies."