EXCLUSIVEThe REAL North-South divide revealed - and why it's all to do with how you eat your fish and chips
It's a question that has rankled England for years - just where does the North-South divide lie?
Researchers have tried for years to settle the debate, drawing lines as far north as Manchester and as far south as Leicester.
Some have drawn a straight line linking the Severn Estuary with The Wash - a deep score in the landscape that cuts across Coventry and Northampton and bisects Cheltenham.
Studies have tried and failed to definitively declare the driving force setting the geographical barrier: health, poverty, inequality, house prices, political voting patterns and public investment.
Many have tried to identify the point at which 'hello' becomes 'ey up'. None have yet succeeded.
But a new survey of Brits argues that the true north-south divide isn't dictated by anything as mighty as paramount as politics.
It is, in fact, dictated by what we put on our fish and chips.
A sweeping survey of 2000 people across the UK has revealed that there is a clear and unequivocal geographical divide in the condiments drizzled, squirted and squeezed onto our chippies, chippers and fish suppers.
The question of the north-south divide has been settled, according to supermarket Iceland - which has decided it is based on how you eat your fish and chips
The poll, conducted for supermarket Iceland, found that curry sauce was the sauce of choice in areas such as the East Midlands, North East, North West, Yorkshire and Wales.
But in regions such as Hertfordshire, London, Devon and Cornwall and the West Midlands, ketchup is king among takeaway lovers.
The true definition of the north-south divide, the supermarket argues, is in fact not a clear divide at all.
It is, in fact, a squiggly line running north from Bristol, looping around the West Midlands before gravitating along the northern edge of East Anglia.
Paul Dhaliwal, chief commercial officer at Iceland, said the poll had originally been conceived to identify the ways chip shop orders differ across the country: mushy peas; scraps; pickled onions.
But it was when they examined the sauciest parts of the data that they realised they had happened upon a decisive trend.
'We noticed a clear divide between the sauce on Northern and Southern orders,' he said.
'We have now officially identified the dividing line between the two regions - and its curry sauce that's the outlier.
'The debate between where the North starts can now be settled: if you live in Wales and Nottingham, you're Northern.
'But if you live in Birmingham, Coventry or anywhere below Northampton, consider yourself Southern.'
A poll of 2,000 Brits conducted for supermarket Iceland identified a clear preference for ketchup among Southerners
Northerners, meanwhile, are much more likely to have curry sauce with their Friday night treat
The supermarket is so convinced of the split that it has decreed a new North-South divide
Exclusive data provided to MailOnline reveals that every region surveyed identified a clear relative majority preference of either ketchup or curry sauce.
Across the 'North', between 39 and 46 per cent of cod-scoffers say they have their dinner with curry sauce, while in the 'South' between 39 and 49 per cent make ketchup their condimental companion.
And thanks to the majority of the population being based above the newly defined line, curry sauce wins out as a chip shop favourite against ketchup in the rankings of what Brits love to order the most: 29 per cent versus 22 for the red sauce.
Northerners like scraps - the crunchy leftover batter - on the side; Southerners would rather have a battered sausage as an extra treat.
There are two unifying (or is that unifrying?) factors: both agree that a portion of fish and chips is not complete best with lashings of salt and vinegar, and a side of mushy peas.
Around 42 per cent of Brits apply seasoning, and 28 per cent say their meal isn't complete without the green side.
To mark the creation of the new geographical divide, Iceland plans to park a fish and chip fan just north of the new border - outside its Skegness supermarket - from 11.30am on Friday.
There will be free fish and chips while stocks last, a 'sauce' told MailOnline.
For those who can't make it down, Iceland has relaunched its range of Harry Ramsdens frozen fish and chips across the UK including fish, chips and, yes, pots of curry sauce.
