Lewis Baston is author of Reggie: The Life of Reginald Maudling and several books about British general elections. He is a consultant on politics, elections and constituencies.

This August marks the 70th anniversary of Royal Assent for the New Towns Act of 1946 – part of the ambitious social reform programme of the 1945 Labour Government which was ultimately embraced by the Macmillan Government. These little Brave New Worlds have proved strange political laboratories, and produced more than their fair share of surprising election results.

I have an unfashionable liking for the New Towns, particularly those born in the initial flush of post-war idealism. They make my social democratic heart flutter because they are still little chunks of the post-war dream: new industries producing jobs, excellent low-density housing for people regardless of class, a pleasant environment of parks and gardens, bold modernist civic architecture and a mostly successful attempt to build it in neighbourhoods that would have a sense of community. Harlow’s avenues curve gently through the parkland landscape, as its guiding planner Frederick Gibberd intended: indeed, he adopted the town as his home. But while founded as social democratic utopias, their story will also gladden the hearts of conservatives.

The Attlee-era New Towns came in two broad types. A few were associated with local industrial developments – the ill-fated new coalfield around Glenrothes and the two County Durham New Towns of Peterlee and Newton Aycliffe. Most of the New Towns, though, were intended to be destinations for housing and jobs for people displaced out of the big cities. Hertfordshire and Essex took the largest concentration: Stevenage was the first among them, plus Harlow, Hemel Hempstead, Welwyn, Hatfield and Basildon. Bracknell and Crawley were also near London; Cwmbran and East Kilbride were also part of the first programme; Corby (1950) was the last designated under Attlee.

The first New Towns were not welcomed by the mostly Conservative locals in the smaller towns and villages that would be subsumed in these new working class settlements. A sign went up at the station in (Old) Stevenage renaming it ‘Silkingrad’ after the then Planning Minister, Lewis Silkin. But on returning to government in 1951, the Conservatives had their ambitious plan to build 300,000 houses a year, and therefore continued with New Towns, designating another at Cumbernauld. They even created a new mechanism for rapid new building through the Town Development Act of 1952, this time with a bigger role for local authorities (quasi-New Towns such as Basingstoke and Swindon owe their modern form to this Act). There were backbench Conservative discussions about the electoral impact which, as Reggie Maudling noted, came to the conclusion that working class, unionised populations arriving in the Tory shires were a worrying thing, but had nothing to say about how to respond.

However, even by the late 1950s the electoral behaviour of the New Towns was not shaping up as expected. In 1959, most observers expected Labour to gain the marginal seats swollen by New Town building, regardless of the national trend, but the Tories held on in Hitchin (Stevenage), Billericay (Basildon) and Epping (Harlow), despite the influx. It may be that the New Towns ‘decanted’ a more Tory-inclined slice of the big cities’ population: skilled, well paid working class voters, following the jobs in modern industries succh engineering and chemicals to the New Towns, and enjoying the material affluence of the Macmillan era in their new surroundings. It may also be that volunteers to move to the New Towns were people who felt less emotionally attached to the traditions – including Labour voting – of working class inner cities.

While the New Towns were giving a cautious embrace to the Tories, the gesture was reciprocated with enthusiasm. In 1961, the Macmillan government took a sharp turn towards indicative planning, regional policy and high public spending, and with that change came a wave of New Town designations, all away from London: Skelmersdale and Runcorn near Liverpool; Dawley (Telford) in the West Midlands; Redditch near Birmingham; Washington between Newcastle and Sunderland, and Livingston midway between Edinburgh and Glasgow.

During the 1960s, the New Towns gained their reputation as marginal seats that neither main political party could take for granted. It can be argued that the perception of the skilled working class voter as the crucial swing elector in British elections owes a lot to the New Towns. Hitchin and Epping fell to Wilson’s Labour in 1964, but Billericay resisted until 1966. The 1970 election confirmed the swing status of the New Town seats, as Billericay and Epping reverted to the Tories (electing Robert McCrindle and Norman Tebbit respectively), while Hitchin stuck with Labour. The Wilson government, meanwhile, had announced another generation of New Towns, mostly grafted on to large existing towns (Northampton, for instance) ,although the biggest was the New City of Milton Keynes in north Buckinghamshire.

The New Towns seemed to be living up to the fears of the Tory backbenchers, after all, in the next elections. Harlow got a seat of its own, and the Tories came third in its inaugural contest in February 1974; Labour gained Hemel Hempstead and Welwyn & Hatfield in October of that year – the first time either seat or its predecessors had ever voted Labour. In Scotland, New Towns were among the best areas for the SNP, although there was a bizarre interlude between the 1974 elections during which the windswept concrete estates of Cumbernauld had a Conservative MP. Neither the English nor the Scottish trend was maintained in 1979, as the English New Towns reaffirmed their marginal status, and the Scottish ones flipped back to Labour. The Tories gained Basildon, Telford (Wrekin) and three Hertfordshire seats, including Hertford & Stevenage, where Shirley Williams lost her seat. Labour narrowly retained Harlow.

The New Towns were fertile ground for the Right to Buy policy, being composed largely of high-quality homes occupied by fairly prosperous tenants who had lived there since the houses were built. The appeal of this Conservative policy was strong in 1979, and it bolstered the party’s strength in the next three general elections. The New Towns also reacted badly to Labour’s division and incompetence in 1983, and delivered some shockingly bad results, such as a poor third place for the party in Stevenage. Basildon became the symbol of the 1992 election, although a surprisingly strong Conservative vote was nothing new (as in 1959, 1964, 1979 and perhaps, most of all, in 1983, when boundary changes had supposedly made it safe for Labour). However, to the frustration of Thatcherites, the enthusiasm of Scottish New Town dwellers for the Right to Buy did not translate into any love for the Conservatives.

At municipal level, most of the New Towns acquired their own local councils in Peter Walker’s Local Government Act of 1972, and from the inaugural elections in 1973 onwards they were, at least at municipal level, Labour strongholds through thick and thin until the second Blair term. Some of them were fairly left-wing, as a drive along Harlow’s Allende Avenue shows to this day, although Basildon is now far from being the ‘Little Moscow down the Thames’ that Patrick Jenkin described in 1982. Throughout the 1980s, Harlow and Stevenage elected Labour councils by huge majorities even while voting for Conservative MPs, confounding those of us who were using local elections as a guide for what might happen in general elections.

But the New Towns were still volatile, and swung even more fiercely to Tony Blair in 1997 than the rest of the country: Labour swept the board, with the sole exception of Bracknell. In 1997 and 2001, Labour’s lead in the New Towns was bigger than in England as a whole, but then the ever-changing political mood switched again, and there were above-average swings to the Tories in 2005 and 2010. In 2015, there was an English swing of 0.6 per cent to Labour, but a New Town swing of 0.8 per cent to the Conservatives, as a result of which Telford went Conservative for the first time since 1983. Since 1997, England has swung 9.6 per cent to the Tories, but the New Towns have swung about 16 per cent in the same direction. Their voting behaviour habitually overdoes the national swing.

The volatility of the New Towns has been associated with their position at a political and demographic crossroads. They are working class, but generally prosperous and aspirational; they still have very high levels of social renting, but the idea of a home owning society has a strong appeal; residents tend to work in the private sector, but care passionately about the quality of state provision in education and health. They have more families and older people, and fewer students and professionals than most constituencies. Most are also whiter than the urban English average, although some, such as Milton Keynes and Crawley, are pretty diverse. Labour may need stronger class politics, as well as a cross-class appeal, to rebuild its foundations in the New Towns, because if an election is mainly determined by the cultural divide most of the New Towns are on the right. Probably only Welwyn Hatfield voted to Remain in the EU and, in many of them, the Leave vote exceeded 60 per cent. The results in 1983 show that nostalgic socialism is probably not going to be much help.

There have been a other developments which suggest that the blue shift in the New Towns might have some staying power. One is the growth of privately-built commuter estates on the edge of several of them, as with Church Langley in Harlow and Maidenbower in Crawley. Another is the Conservatives’ ability to sustain reasonable results in local government elections, in contrast to the 1980s: Harlow’s local elections (other than the UKIP year of 2014) have had the same pattern of Labour seven wards, Conservatives four ever since 2011.

The marginal status of the New Towns means that their MPs rarely get to sit around the Cabinet table: Shirley Williams and Jacqui Smith both did, but Harlow’s Robert Halfon was the first to make it under the Conservatives from one of the pure-bred New Towns. Halfon is an interesting figure in thinking about the politics of the New Towns;:a persistent candidate who first stood for the seat in 2001 and built up astonishing name recognition even before he won the seat in 2010. As a backbencher, he was a shrewd advocate of New Town residents’ concerns such as fuel duties, and we have yet to see what the fleshed-out version of White Van Conservatism looks like – but it may be the best political strategy yet for retaining these fickle towns. None the less, as the unexpected twists in their 70-year political history demonstrate, they are never to be taken for granted. After all, they have also shown enthusiasm for some new political forces when they arise, like the SDP and UKIP.

First footnote: ‘Classic’ New Towns: Harlow, Welwyn Hatfield, Stevenage, Hemel Hempstead, Bracknell, Crawley, Milton Keynes North (East), Milton Keynes South (West), Corby, Telford, Redditch, Basildon (two constituencies included from 2005 notional results onwards).

Second footnote: Brian Mawhinney, in John Major’s Cabinet, represented Peterborough, which is one of the late-generation New Towns but a city and constituency that existed long before designation in 1967.