Richmond Park by-election campaign entering final phase
Campaigning is entering its final phase in the Richmond Park by-election ahead of Thursday's vote.
The Lib Dems say there are "closing the gap" on sitting MP Zac Goldsmith, the former Tory who triggered the poll over his opposition to Heathrow expansion.
Both the Lib Dem and Labour candidates say they will vote against Brexit in the event of a Parliamentary vote.
Mr Goldsmith is backed by local Tory MPs and UKIP while the Green Party is backing the Lib Dems.
With the Conservatives, UKIP and Green Party not fielding candidates, there are eight people standing in the election.
Mr Goldsmith won the seat with a majority of more than 23,015 in last year's general election but the Lib Dems are targeting the constituency - after making big gains in the Witney by-election last month - which they held for 13 years until 2010.
Leader Tim Farron and predecessor Nick Clegg are among those to have been out canvassing in the seat while many of the party's more than 100 peers are visiting the constituency - which encompasses Richmond, North Kingston and New Malden in south-west London - in the 48 hours before polls open.
Former Lib Dem business secretary Vince Cable, who was MP for the neighbouring seat of Twickenham and Isleworth until last year, told the BBC on Sunday that Mr Goldsmith's lead over Ms Olney was "narrowing" and he expected the result to be "very close".
Mr Goldsmith, who is standing as an independent, told BBC Breakfast that the by-election was a vote on his record as a MP since 2010, including his support for the UK leaving the EU, but primarily on his longstanding opposition to a new runway at Heathrow now backed by the government.
"If I lose this by-election, Heathrow will win," he said. "A vote for me is against Heathrow expansion".
With all the leading candidates opposing Heathrow expansion and with the constituency having voted clearly in favour of remaining in the EU in June's referendum, the Lib Dems have sought to turn Thursday's poll into a vote on the government's Brexit negotiating strategy and aims.
Ms Olney told the BBC that, if elected, she would have a "personal mandate" to vote against triggering Article 50 - the official mechanism for leaving the EU - should Parliament get to decide on the issue.
"It appears people want to send a very clear message [on Brexit]," she said. "People want better representation on this issue."
Labour candidate Christian Wolmar has also said he would oppose the start of official talks on the UK's separation from the EU - putting him at odds with many within his own party who argue the Leave referendum result must be respected.
"Brexit is bad for Britain," he told BBC Radio 4's Today. "We know that from the dodgy Nissan deal, we know that from the fact that some 30,000 civil servants are going to have to untangle it. It would be a complete vote into the unknown."
At the 2015 election the then Conservative Zac Goldsmith got 34,404 votes, the Lib Dems 11,389, Labour 7,296, the Green Party 3,548 and UKIP 2,464.
Green co-leader Caroline Lucas has called for party supporters to back the Lib Dem candidate as the best way of ousting Mr Goldsmith - as part of attempts to form a broader electoral alliance among "progressives".
But former London Assembly member Darren Johnson has criticised the decision not to field a candidate in the constituency.
Voting takes place between 07:00 GMT and 22:00 on Thursday. The result is expected in the early hours of Friday. There will be a This Week by-election special on BBC One covering the result.
Here are all the candidates, in alphabetical order of surname:
- Zac Goldsmith, Independent
- Howling Laud Hope, The Official Monster Raving Loony Party
- Maharaja Jammu and Kashmir, One Love Party
- Sarah Olney, Liberal Democrats
- David Powell
- Dominic Francis Stockford, Christian Peoples Alliance
- Fiona Natasha Syms, Independent
- Christian Wolmar, Labour Party