The most recent polls show no sign of the Conservatives narrowing Labour's lead and that the Lib Dems are sustaining their best election campaign ratings for 20 years.
The Conservatives have campaigned relentlessly on asylum and immigration and claim that their success on this issue is not reflected in the opinion polls. The latter point cannot be disputed.
They achieved 33% of the vote in the 2001 election. In the eighteen polls published between 17-26 April, their share was 33% or less in fourteen of them.
The most recent issue to raise its head is the legitimacy of Britain's participation in the Iraq war.
At first sight it seems strange that the opposition parties should devote time to this subject, given that it barely appears on the public's radar screen according to the polls.
But this is no paradox: the real issue being raised is Tony Blair's general trustworthiness.
Politicians and trust are two words British people rarely use in the same sentence. But the Conservatives and the Lib Dems have their own reasons for focusing on it.
For the Conservatives, the long running debate about whether Tony Blair misled the British people over the justification for the Iraq war helps them chisel away at Mr Blair's reputation on domestic political issues before polling day.
The strategy is to persuade voters that if Mr Blair did not tell the truth about Iraq then can he be trusted to tell the truth about the state of the health service, crime and the economy.
The Lib Dems on the other hand hope capitalise on anger over the Iraq war among middle class Labour voters.
They need such voters to switch to them if they are to survive in the seats they won from the Conservatives in the last two elections and if they are to take even more (mostly) Conservative scalps this time.
Labour's nightmare is that some of their 2001 voters will drift to third-placed Lib Dem candidates in key marginals with the result that a number of them will fall to the Conservatives.
To avoid such a fate, Labour needs to motivate its supporters to turn out on polling day.
And the polls suggest that the bigger the turnout, the more promising are Labour's re-election prospects. However, the same polls also suggest that Labour is still struggling to persuade a significant percentage of its supporters to cast their votes.