As the Tories make a concerted effort to win over ethnic minority voters, the Guardian's Hugh Muir explores the thinking behind this latest campaign ploy in his foreword for Runnymede's Race and Elections report.

It is untrue to say our politicians cannot agree on anything, for they agree that the election of May 7 2015 will be the most important in a generation. In keeping with our fiercely partisan politics, each has distinct reasons for believing that to be the case.

Most also agree that one of the most urgent requirements of those who scrap for votes - currently and in the future - is a better understanding of how race and culture now impacts on the British electoral process. Once they had a working knowledge. But with fast moving demographic re-alignment in towns, cities and hamlets around the country, the tectonic plates are shifting. Around them they see ties loosening, traditions eroding, certainties unravelling.

With ethnic minorities projected to make up a quarter or more of Britain’s population by 2051, compared with 8% in 2001, the parties do understand that new thinking is required; not just by those that wish to represent, but by those who aspire to form governments and municipal administrations. They know that the need to grasp new realities is greater than ever. And yet - here is the oddity - none can really be said to have risen to what could become a life-or-death challenge. The loser on May 8 may rue that failure as an opportunity squandered.

Talk to Labour officials and they will emphasise the importance of the party continuing to appeal to the majority of Britain’s voting minorities. These are ties going back over a half a century and replicated down generations.

But they will know of grassroots disgruntlement that the relationship has been left untended. The party promises that if elected in May, it would enact a radical plan to tackle race inequality. But in the interim there are concerns that Miliband’s Labour has done too little to address the specific problems of traditionally supportive minorities for fear of losing more support among white working class communities. Concerns that the party has been reluctant to boost minority representation within parliament with the same determination that led to the increase of more female Labour MPs via all women shortlists. In April, Diane Abbott warned her party that the Conservatives are on their way to overtaking Labour when it comes to electing more black and Asian MPs.

Labour faces questions connected with the pronounced shift of minorities from inner cities into the suburbs. Will those who supported Labour maintain that allegiance, or will they absorb the outlooks of neighbours who might support other parties?

The Conservatives also have much thinking to do. The Tories secured just 16% of the minority vote in 2010. In a time of political plenty, such underperformance was regrettable, no more. But with the shrinking of the traditional Tory vote reservoir in white, middle England and the projected demographic shift of minorities into Tory heartlands, party bosses understand that their position is not sustainable.

Are minorities conservative? Many, many are. The pollster Lord Ashcroft and others have produced research showing the relative extent to which some minority communities are more likely to connect with the Tory message than others. The key problem for the party is branding. In years of past, it didn’t matter numerically that the Tories presented as uncomfortable and hostile to diversity. The party carried the millstone of Enoch Powell’s Rivers of Blood speech - despite Powell’s immediate dismissal by Edward Heath. There was the campaign in Smethwick in the 1964 General Election, with its unofficial slogan “If you want nigger for a neighbour, vote Labour”. There was the tacit approval of Thatcherite right wingers for backbenchers who would occasionally make the news with racist remarks. There was Thatcher herself, dog whistling with talk of Britain being “swamped” by those of alien cultures.

Marketeers like brands. They communicate almost subliminally the form and shape and values of the product on offer. A positive branding endures. But so does a negative one. I once discussed this with Grant Shapps, the Conservative party chairman. He seemed puzzled that so few minorities felt able to embrace the Tory brand. I have to take my hat off to you, I told him. Given the conservative instincts of so many minorities - people who exhort their own self reliance, people who revere family, church and institutions - for you to pick up so few votes from them is virtually an act of genius.

So the Tories have been thinking, as a sailor will think when the boat has sprung a leak. They have 18 ethnic minority candidates in held seats, compared - at the time of writing - with Labour’s 19. And they have been doing things selected minorities might like; more action regarding possible corruption on the totemic Stephen Lawrence case and a thorough review of stop and search by the police. A reduction in air passenger duty, allowing minority Britons to take cheaper flights back to south Asia and the Caribbean. Action to stop the banks moving out of the remittance market used by UK Somalians to send money home to their families.

But if only it were that easy. Here’s a conundrum still baffling Tories; how to be liberal enough to negate the negative branding and build minority support, without appearing so liberal that they lose the middle class right and the white working class vote to UKIP. How to look tough on immigration without being accused of an attack on difference? Problems like this have been identified by the party but require attention and sustained determination from the top to achieve solution. Thus far, they haven’t had it.

Does this represent an opportunity for the smaller parties? Perhaps, but with the Liberal Democrats in retrenchment, few believe this will be the time for it to deal with a lamentable record in terms of race and front line political representation. It too has a branding problem; not Tory hostility - just the impression of cliquism and all smothering apathy. Addressing that might one day transport the party to a healthier state.

There are competing currents. Some argue that in the politics of 21st century Britain, race matters less in terms of belonging and party allegiance than class. But perhaps that is the rose tinted view. And still there are specific communities who are communally and collectively ill-served by the way we do our politics. For them, the argument as to whether their disadvantage stems from race or class seems moot.

For all that - survey the landscape, read the varied and hugely informative series of papers compiled within Race and Elections by the excellent Runnymede Trust - and now must strike you as a significant moment; when the votes of those who live outside the walls of white Middle England matter, and increasingly so. What altruism has failed to achieve over all these years, numbers will.