The main political party leaders are continuing to push their election pledges to voters, as the campaign enters its final few days.
Conservative leader Boris Johnson says in an open letter that Thursday's poll is "historic" and a choice to "move forwards" after Brexit.
Labour leader Jeremy Corbyn said it was a "chance to vote for hope" and he had "the most ambitious plan to transform our country in decades".
The UK goes to the polls on Thursday.
Ahead of this, the candidates are travelling around the country in a bid to spread their election messages.
Among the manifesto pledges being highlighted by the main UK parties on Sunday are:
- A Conservative promise to introduce an Australian-style points-based immigration system to control unskilled migration
- A Labour plan to "head off the social care crisis" by offering free personal care for older people in England and an additional £10bn of funds by 2023-24
- A "regional rebalancing" programme from the Lib Dems, which would see £50bn invested in infrastructure outside of London
Meanwhile, SNP leader Nicola Sturgeon is warning that "the very future of Scotland" is at stake in the election.
She is appealing to voters to back her party "to escape Brexit, protect the NHS, and to put Scotland's future in Scotland's hands".
And Liberal Democrat leader Jo Swinson told Sky News her party was looking to make "real progress" by increasing its number of MPs on Thursday.
She added: "We will be absolutely working to stop Brexit, doing so in a co-operative way with others who share our values and share that goal."
In his letter to voters published in the Mail on Sunday, Mr Johnson says the election will be one that "shapes future decades", urging voters to create a "working Conservative majority government that will get Brexit done, end the uncertainty and allow Britain to move on".
The Conservatives have released some details about how their points-based immigration system would work.
Writing in the Sunday Express, Home Secretary Priti Patel, said it would start in January 2021 and aimed to "attract the best talent that our country and economy needs, while reducing overall numbers".
There would be fast-track entry to the UK for entrepreneurs and some people working for the NHS, and sector-specific schemes for low or unskilled workers to meet labour market shortages.
Speaking to Sky News, Mr Johnson declined to say if he would resign if he failed to win a majority in the House of Commons.
He said: "What I'm going to do is concentrate on the five days before us, because that is what I think the people of this country would expect."
In the same interview, the prime minister insisted there would not be any checks for goods travelling from Northern Ireland to Great Britain under his Brexit deal.
A leaked Treasury analysis document was "wrong" to suggest this would be the case, he said.
And in a short speech at the Conservative Party's headquarters, Mr Johnson warned his supporters that the "horses can still change places" in the final week of the campaign, saying: "This is a close-fought election."
Meanwhile, Labour is restating its plan to help alleviate pressure in social care through the introduction of free personal care for older people.
The party says its new funding will help working-age adults and pensioners with care costs, which will also be capped under the proposals.
According to the King's Fund, providing free personal care would require an additional £6bn on top of planned spending by 2020-21, taking the social care budget to roughly £26bn.
Labour is also talking about its own research on the issue, which it says shows 9,290 people have approached their local authority since April 2017 for help with care costs after draining their savings.
At a rally at Bangor University in north Wales, Mr Corbyn attacked "cruel" Universal Credit - which his party has said it would scrap.
He also repeated his pledge to compensate so-called Waspi women, who lost out on years of state pension payments when the retirement age was raised under the coalition government.
Shadow chancellor John McDonnell BBC One's Andrew Marr Show that Labour would "transform our economy" if it won a parliamentary majority at the election.
He added: "I want to make sure our economy works for everybody... It means transforming capitalism into a new form."
Mr Johnson says he wants to focus on people's priorities, including urgent investment in the NHS and action on the cost of living.
Speaking ahead of the last stretch on the campaign trail, Mr Corbyn said Mr Johnson "cannot be trusted to deliver Brexit, or anything else".
He said Labour would "rescue" the NHS and "get Brexit sorted".
Elsewhere, the Lib Dems said their plans would "address the historic investment disparities between our nations and regions".
Its plans would boost railway electrification, increase the availability of charging points for electric vehicles and improve broadband access, the party added.
Liberal Democrat deputy leader Ed Davey said: "Neither Labour or the Tories can square their spending promises today with the cost of Brexit. They are writing promises on cheques that will bounce.
"Every vote for the Liberal Democrats is a vote to stop Brexit so we can invest billions across the UK, helping to tackle ingrained inequality."
On the campaign trail in Sheffield, Liberal Democrat leader Ms Swinson also encouraged her supporters to make a final push for votes, telling them: "When you wake up and deliver those 'good mornings' when there's frost on the ground, I want you to know that everything that you do will make that difference."