The Government has "catastrophically" failed to control immigration, Ukip has said.
After new figures showed net migration to the UK soared to 318,000 in 2014, Nigel Farage, the party's leader, said David Cameron's claim to be "pulling up the drawbridge" was "absurd".
Cameron's claim to be pulling up the drawbridge is absurd http://t.co/WToFDm2Y7E Net migration up again, now 318,000
Ukip's only MP, Douglas Carswell, said Government plans to strip illegal workers of their pay were "mad" and would "persecute a handful of illegal workers".
Ministers cannot control immigration. Yet these supposed "One Nation" leaders introduce rules to persecute a handful of illegal workers. Mad
Steven Woolfe, the party's migration spokesperson added: “Today’s government announcement on illegal migration is a smoke screen to mask today’s appalling immigration statistics.
"In almost every area, net migration, overall UK immigration, EU immigration, non-EU immigration, sham marriages, bogus students, overstayers; the government has failed catastrophically."
The Ukip leader Nigel Farage has responded to resignation of Ukip MEP Patrick O'Flynn from the party's fron bench by saying he accepted it with "sadness".
"Patrick O'Flynn came in person to tell me he had realised that he had made a mistake and, being the honourable man that he is, tendered his resignation as UKIP Economics Spokesman.
"I accepted his resignation with some sadness, not least because he is very able and has been a great asset to the team. He continues to be a committed UKIP member and MEP."
Ukip MEP Patrick O'Flynn today said he had stepped down as the party's economics spokesman and apologised to leader Nigel Farage for calling him "snarling, thin-skinned and aggressive".
The "compassionate, centre-ground" position outlined in Ukip's general election manifesto is where the party needs to go, its deputy chairman has said. Suzanne Evans dismissed the row over Nigel Farage's leadership, insisting the problems related to advisers who had kept him in their pocket.
She said they had been trying to take the party back to what it was several years ago, but stressed its future lay in diversifying and becoming more inclusive.
Ms Evans told the Andrew Marr Show: "I don't think anyone hates anyone. "I think we have had some problems with advisers around Nigel, who very much kept him in their pocket if you like and I think he has had too much influence from them."
Douglas Carswell, Ukip's only MP, has suggested that Nigel Farage "take a break" from the party leadership and said his pre-election comments about HIV patients had been "ill-advised".
Writing for the Times (£), Carswell said: "Elections are enormously stressful. The immediate aftermath of one is not the time to take big decisions about the future. It takes a team to get the answers right."
He also appeared to echo concerns raised by economic spokesman Patrick O'Flynn, who claimed that Farage had come across at times as "snarling, thin-skinned" and "aggressive".
At times, Ukip has failed to strike the right tone. By all means we should highlight the problem of health tourism. But we need to admit that using the example of HIV patients to make the point was ill-advised.
Ukip has been at its most persuasive when we have been most optimistic. Anger is never a great way to motivate people — at least not for very long.
Ukip's former chief of staff has hit out at the party's only MP and its campaign chief for dragging the party into "major national disrepute" in the row over Nigel Farage's leadership.
Raheem Kassam, who will leave the party at the end of the month, backed Mr Farage and accused Douglas Carswell MP and party economic spokesman Patrick O'Flynn of acting on "purely selfish terms".
Mr O'Flynn had said Mr Farage had turned the party into a "personality cult" with his decision to continue as leader despite resigning after failing to win a seat in the election, as the resignation was rejected by the National Executive Committee.
Speaking on BBC Radio 4's Today programme, Mr Kassam called for Mr Carswell and Mr O'Flynn to leave the party and said they had "gone after" him.
I feel a bit of responsibility in the sense that the characters who brought this up, namely Douglas Carswell and Patrick O'Flynn, are acting on purely selfish terms.
They saw me as Nigel's sort of body armour and that if they went after me that they would get to Nigel.
These people are not acting in the best interests of the party, what they are doing is bringing the party into major national disrepute and I don't think they have a place in the party.
Nigel Farage has said that he had been "determined" to resign when he had handed in his notice as leader of Ukip but "they dragged me back over the wall."
Speaking on BBC Question Time, Mr Farage ruled out quitting following Ukip infighting and said that he has a "phenomenal" level of support within the party.
Nigel Farage has said a Ukip leadership battle would be a "massive, massive mistake" and dismissed the current row within the party as "people letting off steam".
Speaking on BBC Question Time, Farage said the "level of support for me in the part is phenomenal" and claimed any change in leadership would be a bad idea with an EU referendum due, potentially as soon as May 2016 in his view.
He said he was "disappointed" that colleague and party economic spokesman Patrick O'Flynn had accused him of becoming a "snarling, thin-skinned, aggressive" man, but said it was a result of the election campaign creating "a huge amount of pressure".
"I'm sure the others would agree, and we maintained discipline as a party extraordinarily well during this general election compared with the past. The election's over, people are letting off steam, and we've seen one or two people fighting personal wars against each other."
Nigel Farage has told ITV News he believes he has lost the confidence of his party.
Asked when arriving for tonight's BBC Question Time, Farage replied: "Big time".
However, the Ukip leader decline to say whether he would resign from the party leadership.
Ukip spokesman Patrick O'Flynn should resign over his "wholly unprofessional" comments about Nigel Farage, the party leader's outgoing chief of staff has said.
It was confirmed today that Raheem Kassam had left his job, but Mr Farage's former adviser insisted that his contract was always due to expire at the end of May.
"I wish Nigel all the best, Nigel is clearly the best person to lead the party; he's clearly the best communicator in British politics and for Patrick O'Flynn to call him 'snarling' I think shows what sort of pedigree Patrick O'Flynn has in politics," he told Sky News.
Kassam revealed that he is returning to journalism with Breitbart London where he would "scrutinising quite heavily what the red Ukip team are trying to do with the organisation".