Theresa May has signalled that she hopes to meet her manifesto target of reducing net migration to Britain to the tens of thousands by the end of the next parliament.

With just a week to go before polling day, the prime minister repeatedly returned to the issue of immigration on Thursday as she toured Labour-held constituencies in northern England and Midlands and sought to inject fresh vigour into the Conservative campaign.

The policing minister, Brandon Lewis, told the BBC’s Daily Politics on Thursday morning: “We want to see migration levels come down to sustainable levels, which we think is tens of thousands, over the course of the next parliament.”

No firm date was set for the pledge in the Tory manifesto, but when asked about Lewis’s remarks, May said: “That’s what we’re working for.”

The Guardian view on May and the constitution: what does she mean by that? | Editorial Read more

Later, in a question and answer session with workers at a furniture factory in Pontefract, West Yorkshire, the prime minister stressed her determination to address the issue “because of the impact that immigration has, when it’s too fast and too high and uncontrolled, on people”, adding: “And it does have an impact on people, particularly at the lower end of the income scale.”

May was challenged by one worker from the EU, who said that about half of the workforce at the factory were from other countries,. “We are very afraid, some of us,” the worker said. May said she would like to protect the rights of EU workers in Britain but first wanted to secure the future of British citizens living in other EU countries.

A small crowd of Labour activists held up banners outside the factory as May’s battlebus drove in.

Facebook Twitter Pinterest A billboard in Manchester. Theresa May toured north-east constituencies on Thursday. Photograph: Oli Scarff/AFP/Getty

The Labour MP Jon Trickett, whose Hemsworth constituency includes the site, said: “No doubt Mrs May has had a warm Yorkshire welcome, albeit in her usual sanitised bubble. But she shouldn’t mistake that for support for her mean-minded ideas. She avoided meeting any of the 18,496 pensioners in our area who are living in fear that they may lose their winter fuel allowance or face having a dementia tax on their homes.”

May’s migration pledge, which appeared in both the 2010 and 2015 Conservative manifestos but was never met, is controversial with senior Tories, including some Cabinet ministers, who believe that putting the brakes on immigration will hit the economy hard.

The former chancellor George Osborne has used his new job as editor of the Evening Standard to criticise the policy. But the Conservatives believe tough talk on immigration will play well for them in the final few days before the general election.

Earlier, speaking to an audience of party activists at a construction business in Guisborough, May painted a rosy picture of post-Brexit Britain, saying: “Every vote will be a step towards that brighter future that we will build, together.”

In a marked shift of tone from recent days, she stressed a commitment to funding the NHS, building grammar schools and improving further education to claim that getting the right Brexit deal would underpinthe social reform agenda at home.

Labour and the Tories start to spell out their differences on Brexit | Dan Roberts Read more

“The NHS is the essence of solidarity in our UK, the institution that binds us all together, a symbol of our commitment to each other, between young and old, those who have and have not, the healthy and the sick,” she said. The Tory manifesto promises to boost health service spending by at least £8bn a year by the end of the parliament – though May would not say where the extra funds would come from.

The prime minister linked the immigration pledge with planned changes to vocational education, which she said would prepare British youngsters for jobs available in a post-Brexit economy. “We will invest in the next generation, so the people growing up in Britain today are ready and able to seize the opportunities ahead,” she said, promising to “revolutionise skills education”.

In Wolverhampton on Tuesday, she had issued a series of stern warnings about Jeremy Corbyn’s leadership of Labour, including the claim that he would be “alone and naked in the negotiating chamber” when Brexit talks started in earnest just after the election.

But her Guisborough speech focused more on possible positive aspects of the next five years and she ended the day speaking to an enthusiastic crowd of supporters at Pride Park, the Derby County football ground, telling them this was “a vitally important election” and pressing home her message that losing just six seats would lead to a hung parliament.

She shrugged off the idea that she had ducked Wednesday night’s seven-way televised debate, which Corbyn did attend. And she refused to be drawn on Boris Johnson’s claim that the audience was biased, saying only: “What I think about last night’s debate is that Amber Rudd [the home secretary] did an absolutely excellent job.”

