The UK Independence Party poses a "mortal threat" to the Conservatives' chances of winning the next election, the shadow foreign secretary has told ITV's The Agenda.
Douglas Alexander told host Tom Bradby that he took the threat from Ukip "very seriously" but added: "I think you defeat Ukip is not [by] what David Cameron has done: first of all ignore them, then insult them, then imitate them."
But he admitted he was "certainly not complacent" and that Labour "have got a lot of work to do."
Mr Alexander added: "If you are a party that aspires to be the government you can't just offer anger, you've got to offer answers - so in that sense I don't want to be a replica of Nigel Farage, I want to be a remedy. That means offering different policies that give people confidence."
Tom is also joined by the broadcaster Mariella Frostrup, the Countdown presenter Nick Hewer and the Spectator's Isabel Hardman.
The Agenda with Tom Bradby will be broadcast on ITV at 10.35pm.
Get involved in the debate on Twitter during the show by using the hashtag #theagenda
Shadow foreign secretary Douglas Alexander has said Prime Minister David Cameron must "urgently consider reversing his decision" to attend the Commonwealth Heads of Government summit in Sri Lanka this week.
"For months Labour has urged the Government to do more to raise Britain's concern over human rights in Sri Lanka in the run up to the summit," Mr Alexander said.
"If the Prime Minister now chose to reverse his decision to attend the summit - even at this late stage - he would have Labour's full support."
The political fallout from last week's Syria vote has continued with a Cabinet minister saying the results would be a matter for Ed Miliband's conscience and the shadow foreign secretary admitting he was not comfortable with the position Labour now finds itself in.
Speaking on BBC Breakfast Shadow foreign secretary Douglas Alexander said:
The right response is not simply to say something must be done, however loudly. It is to both ask and answer the question 'What steps can be taken to make a horrendous situation better?'
Now, as the Labour Party, we have never in principle ruled out the use of force in Syria. But we haven't yet heard from the Government what its strategic objective would be for any military action.
Would it be to degrade and diminish the capability of Assad to use chemical weapons? Would it be an attempt to try and change the course of a highly complex, intractable civil war?
We simply haven't had those questions answered.
And that's why I do think the Prime Minister should bring Parliament back so that they can offer their case both to politicians and to the people before any decision is taken to commit British forces into combat.
The shadow foreign secretary said the leaks that suggest the GCHQ had tapped data cables "underlines the need" for ministerial oversight of intelligence agencies.
Douglas Alexander said: "The latest reports in the Guardian underline the need for effective parliamentary and ministerial oversight of GCHQ and our other intelligence agencies.
"Whilst GCHQ do vital work to keep us all safe from harm, it is also vital that they do so with the legal framework set down by Parliament, and with proper safeguards in place to protect people's privacy.
"We urged the Intelligence and Security Committee (ISC) to look into these issues raised by the Guardian, and their work is now under way.
"These latest reports reinforce the urgency and importance of the ISC's work on this issue."
Labour’s Shadow Foreign Secretary Douglas Alexander has said there is unease "across party lines" about the Prime Minister's comments on the potential supply of British arms to Syria's opposition forces. In a statement, he said:
For months Labour has called on the Government to answer basic questions about their approach, such as how would the Prime Minister ensure that weapons supplied did not fall into the wrong hands and how would this step help to de-escalate the conflict rather than prolong it?
The G8 is a key window of opportunity for David Cameron to exert pressure on President Putin and it is vital that he uses the coming hours to do so.