Ed Miliband is too concerned with poll ratings to adopt a principled stand on immigration, Diane Abbott has said.
The Labour shadow health minister said the party was danger of entering into a "downward spiral" with the Tories on immigration, after Australian election strategist Lynton Crosby joined David Cameron's team.
"I've spoken to Ed Miliband about this quite a bit," Abbott told Prospect magazine.
"What weighs with him is the polling which shows what the Tories are doing on immigration is popular and it certainly weighs on other members of the shadow Cabinet.
"Not that many members of the shadow cabinet represent a diverse London constituency and views about race and immigration are different once you step outside London if you think about it.
"So I think Ed himself means well and is doing his best but as a party we should do more because, it's what I said, it's a downward spiral."
The Home Office's attitude to immigration has noticeably hardened recently, with tweets of immigration raids, spot checks by UK Border Agency staff and a mobile van telling illegal immigrants in certain boroughs of London to "go home".
Some cite Crosby as the likely source of the initiatives. In a 2001 federal election in Australia, he was said to be responsible for the false claim by some ministers that a boat of asylum seekers had thrown their own children overboard.
"I think he’s going to be a very toxic influence on the type of general election campaign we’re going to have and I think Cameron should sack him," Abbott said.
Abbott's comments will be interpreted as another attack against his leadership following a decidedly anaemic summer.
Former Labour MP Brian Wilson, who served as energy minister under Tony Blair, said Miliband needed to "look in the mirror" and ask himself if he was the right man for the job.
"Ed has now had two years to provide that answer and it is clearly still work in progress. His poll ratings are somewhere between dire and disappointing," he told the Scotsman.
"The latest survey of Labour voters shows that fewer than half of them want him to lead the party into a general election in two years' time."
Former international development secretary Clare Short said Miliband had failed to find a convincing narrative.
"We have heard about the squeezed middle and 'one nation' Labour, but it isn't clear what that means. For a time, Labour’s economic policy seemed to be 'cut a little less'," she told Prospect.
"Now it is, 'stick with government targets'. There is little reason to think much would change with a Miliband government, and that is his major problem."
Miliband was criticised for timing his holiday at the same time as the prime minister, robbing him of two week's worth of news cycles where he could have attacked the government without any heavyweight response.
But since he has returned the Labour leader has continued to operate below the radar.
He is currently understood to be working out the reshuffle of his shadow Cabinet, in which older figures are expected to be jettisoned in favour of fresher faces.
Among those expected to get the boot are Stephen Twigg, who has failed to impress in the shadow education role, and Liam Byrne, who has repeatedly exceeded the limits of the authority when addressing welfare reform.
Sources close to Miliband also say he is working hard on his conference speech, which is expected to mark a significant chapter in his leadership.