A Labour shadow cabinet minister has called on his colleagues to stop talking in the Westminster language of "clipped political soundbites", arguing his party has more work to do before voters will trust them to govern the country.

Rising star Dan Jarvis, the shadow justice minister, said policies are extremely important but irrelevant if voters do not believe that they will be delivered.

Making the case that trust will be the defining issue of the next election, he also called on Labour to go "toe-to-toe" with the UK Independence party, Ukip, by challenging its appeal, after a period of taking for granted and neglecting voters in its northern heartlands.

"The public are so fed up, so cynical with politicians – we have got a huge challenge to address that," Jarvis said. "We have got to convince people we are on their side and working in their interest."

Jarvis made the remarks in an interview with the Guardian to mark the publication of a new book, Why Vote Labour, which is introduced by Ed Miliband. He is the latest in a long line of prospective Labour big-hitters to edit the collection of essays, with the honour going to Rachel Reeves in 2010, Neil Kinnock in 1979 and Roy Jenkins in 1959.

A major theme of the book is loss of trust among voters and the public's "earthquake of dissatisfaction" with traditional politics, illustrated by the Scottish independence referendum campaign and Ukip's success in the European and local elections.

He believes the public are right to think the entire political system is "not fit for purpose" because it does not enjoy the trust of the public, and politicians need to "work out pretty sharpish" what to do about it.

To help address this, Jarvis suggested Labour needs to be about both "bread and roses" once again, referring to an American political slogan that suggests people need a hopeful vision for their wider lives and not just promises about their finances. The book examines how to create an economy for the many, a more inclusive society and a better politics.

"Economic arguments are of course very important … But there are other factors that influence them as well and I think we've seen that in Scotland … I am often quite surprised that in parliament we don't spend very much time talking about things people are interested in and spend their time doing, whether that is engaging in sport, music, film, and the arts."

The book is written in plain English, not thinktank-speak, in the hope that informed members of the public outside Westminster will give it a try. Jarvis, a former army officer, said he and his Labour colleagues could all do better at talking in terms that people understand.

"I know the public just stop listening when we speak in a language of the Westminster village that is about a clipped political soundbite," he said. "We need people who can communicate very effectively, people who have had genuine life experiences outside politics.

"The reality is on all sides of the house that we have frankly far too many people who haven't had that broader life experience and who speak in a language that is only intelligible to people who reside in the Westminster village.

"We have made huge progress but we're now at the point eight or nine months away from the general election where I genuinely believe we are well placed to win it, but we've got quite a bit to do before in the end the public will place their faith and trust in us.

"Trust is going to be the defining issue and the party that wins, that is offered the opportunity to serve and govern, will be the party that is most trusted to deliver. That is up for grabs."

Jarvis, who won his Barnsley Central seat in a byelection in which Ukip came second, said Labour would need to be particularly "muscular" about demonstrating why people should not lend their vote to an anti-politics party. He is not of the view – held by many in the party – that Ukip is best ignored because Farage is primarily taking votes off the Conservatives.

"I wasn't surprised about Ukip's advance. I've seen it coming for some time," he said. "If you get out and talk to the public, you know what the public are thinking and you know they are dissatisfied with the status quo.

"They think there has been a complacency in some of our Labour heartlands for far too long. They know that in some cases, we have neglected the public, we've taken their vote for granted and we haven't taken the time or made the effort to get and talk to people about issues that matter to them.

"In a way we are, to a degree, reaping the whirlwind from a dissatisfaction and through a complacency which we absolutely need to move away from, and I think that we are doing that."

He said Miliband is the best person to resolve the lack of trust as the Labour leader instinctively believes in doing politics in a better way. But the process of convincing people to trust politicians again is "going to be a long march".