Paisley, United Kingdom: If there is one face to remember from Britain’s general election on Thursday, it may well be that of Mhairi Black, a 20-year-old politics student from Glasgow and candidate for the Scottish National Party.

Black would be the youngest member of parliament since 1667 and the embodiment of expected sweeping victories for nationalists in Scotland at the expense of the centre-left Labour Party.

To take her place as the representative for Paisley and Renfrewshire South near Glasgow, she would have to topple one of Labour’s big guns, 47-year-old Douglas Alexander, their foreign affairs spokesman and campaign chief.

A blonde with an easy smile and a no-nonsense style who pronounces her first name “Mary”, Black grew up in a Labour household but has turned her back on a party she says has become too distant from its supporters and left-wing roots.

She says her hometown has been in decline all through her life, with one in five people in Paisley now living in poverty and one in three families forced to resort to food banks for help.

Black campaigned for Scottish independence in a referendum last year that was won by the “No” vote.

Undeterred, she said in an interview two weeks later: “It doesn’t mean the dream has died”.

“The vote result was absolutely heartbreaking, gut-wrenching. But less than a week later I was raring to go. Everyone is pumped up, saying what’s next?” she said at the time.

Her bid for parliament came soon after that.

“I’m coming across door after door of people who are tired of having an MP who’s never here,” Black told the news website BuzzFeed in an interview.

“I’ve lived in Paisley all my life and I can say hand on heart that I’ve seen Douglas Alexander more in the past two months than I have in the last 20 years.”

On Twitter, she has branded him a “career politician”.

During the campaign, she has talked up her leftist credentials and her roots, including full-throated support for local football team Partick Thistle.

In her biography on the SNP’s website, Black said she campaigned against the war in Iraq and worked for the charity Oxfam. She is still a student at Glasgow University and would have to complete final-year exams even if elected.

She cites the referendum as a turning point for her.

“It was always ‘vote Labour, keep out the Tories, vote Labour, keep out the Tories’ but then the referendum came and suddenly everyone woke up,” she told BuzzFeed.

In an interview with the Guardian she said: “My grandfather would turn in his grave if he heard how Labour are behaving now — the bitterness in them.

“The intellect of the party has fallen, the principles of the party have fallen. They started taking people for granted,” she said.

She has been criticised for an abrupt style and threatened to “put the nut in” (headbutt) Labour representatives after the referendum.

She immediately said she regretted her words and put them down to excessive passion.

“I’m not trying to become an MP for a career. I hate that idea. I just want to help people.

“I want to be a signpost. I want to say to people: ‘This is me. This is what I believe in,’” she told The Times.

To those who criticise her lack of experience, she retorts that she is old enough to pay taxes or fight in a war and is undaunted by the prospect of joining parliament at such a young age.

“I’m not the one who should be nervous — it’s all of them down there who have to answer for what they’ve done. They’re the ones who have to be accountable.”