Labour activists have been urged by party chiefs to "move the conversation on" when voters raise the issue of immigration – a leaked document detailing the party's strategy to defeat Ukip showed.
The confidential briefing was sent to dozens of MPs in constituencies where the eurosceptic party threatens to rob the Opposition of the votes needed to return to power at next year's general election, the Telegraph said.
It was exposed just hours before party leader Ed Miliband is due to make a speech seeking to convince the public that Labour has the solutions to fears over the issue – including a proposed new legal crackdown on undercutting local wages.
He will say the party offers "clear, credible and concrete" solutions on an issue that remains high on the priority list for many voters.
However, the 33-page Campaigning against Ukip document warns campaigners that having immigration become a major talking point on the doorstep "does not translate into electoral advantage for us".
"Immigration is the issue people most often cite when explaining support for Ukip," it explains.
"It does not however follow that campaigning on immigration issues and emphasising our policies in our conversations with electors is always the correct response."
While it was important to listen to concerns, it went on, "our focus instead must be moving the conversation on to issues where we have clear policy which tackles the problems people are worried about, whether they express those concerns through the prism of immigration or not."
Campaigners should identify Labour strengths and "encourage them to think more about this … than immigration".
Demanding careful targeting of literature, it says writing to voters about immigration who may not be concerned about the issue "risks undermining the broad coalition of support we need to return to government".
The document exposes the level of disquiet that exists at the top of the party over the threat posed by Ukip, not least in former Labour strongholds in coalfield communities.
Alongside detailed constituency maps pinpointing areas where Ukip switchers are most likely to live, it warns that Labour supporters are being lured away because they "feel that the party has left them behind in pursuit of better-educated, middle-class, white-collar voters".
A Labour spokesman said: "This document sets out clearly how candidates and activists will explain our policies on immigration and seek to explain how they fit into an overall vision for a country that works for everyday working people not just a few.
"Today Ed Miliband will deliver his fourth major intervention on immigration and publish our second key election pledge which is also on immigration. This reflects the priority which he and the Labour Party attaches to an issue on which the Labour Party and many voters have deep concern."
Mr Miliband will use a speech in Great Yarmouth to announce that employers who exploit foreign workers in a deliberate effort to undercut local wages could face prosecution if Labour wins power.
The party has already pledged to make serious exploitation of migrant workers a criminal offence.
But Mr Miliband wants to go further by adopting a German rule which would ensure a "clear discrepancy" between the terms and conditions of local and foreign staff could contribute to a prosecution.
In a speech in Great Yarmouth, Norfolk, he will accuse the Tories and Ukip of "turning a blind eye to exploitation and undercutting because it is part of the low skill, low wage, fast-buck economy they think Britain needs to succeed".
He will insist however that looking after the interests of foreign workers – as well as tougher border controls and benefit curbs – is one of the answers to public fears over the impact of new arrivals on their own prospects.
"We have all heard the most truly shocking stories of people having their wages stolen, and having to live in the most appalling conditions, exploited because they come here from abroad," he will say.
"These practices have an effect on local workers too. Because when people can be exploited for low wages or endangered at work, it drags the whole system down, undercutting the pay and conditions of people here.
"We have a plan to change this. We will increase the fines for firms paying below the national minimum Wage. We will close down loopholes in agency worker laws that allow firms to undercut directly employed staff. We will ban recruitment agencies from hiring only from abroad.
"Today, I am announcing that the next Labour government will go further still: making it a criminal offence to undercut pay or conditions by exploiting migrant workers.
"We are serving notice on employers who bring workers here under duress or on false terms and pay them significantly lower wages, with worse terms and conditions.
"This new criminal offence will provide protection to everyone. It will help ensure that, when immigrants work here, they do not face exploitation themselves and rogue employers are stopped from undercutting the terms and conditions of everyone else."
Labour would not match the Tories' "false promises" on immigration or Ukip's "false solution" of quitting the EU, he said.
"Instead, we will offer clear, credible and concrete solutions which help build a country that works for working people again."
Ukip leader Nigel Farage mocked the campaign document by posting what he said was "Mr Miliband's latest relaunch", a picture of the gesticulating Labour leader with a caption reading: "Immigration? Uh…quick, look over there!"
Shadow work and pensions secretary Rachel Reeves said she had not seen the document.
"This is clearly something that Labour is talking to voters about, and it is our second pledge after our pledge on the deficit last week," she told the BBC Radio 4 Today programme.
"I haven't seen the document but my understanding is those lines have been taken out of context."
Ms Reeves pointed to policies such as counting migrants in and out of Britain, and barring incomers from receiving out-of-work benefits for two years.
"We have clear concrete and considered policies on issues immigration. It's something that myself and other MPs and candidates are talking about every day," she said.
"Some people have immigration as their number one concern. Other people do not. I think it is important when we are out campaigning that we focus on the issues that people are raising with us."