He both oversaw significant road construction (he opened the first section of the M1 motorway) and the closure of a considerable portion of the national railway network with the Beeching cuts.

At that time the telephone network was controlled by the General Post Office, and saw the introduction of subscriber trunk dialling (STD), which eliminated the use of operators on national phone calls, and it has also been claimed that he introduced the first postcodes to the UK, although these were both actually technical innovations which would probably have been inevitable regardless of the presiding politician.

[6] In anticipation of the 1962 Act, the government appointed Dr Richard Beeching as Chairman of the British Railways Board with a brief to recommend and implement such changes as were necessary to end the losses that were growing rapidly at the time.

It may not be entirely a coincidence that as Beeching was closing railway lines, the government was providing funding for the construction of motorways, which were being built by companies in which Marples had an interest.

[9] In 1948 the two men founded Marples Ridgway and Partners, a civil engineering company that started with one five-ton ex-army truck and one crane.

[3][10] When he was made Minister of Transport in October 1959, Marples undertook to sell his shareholding in the company as he was now in clear breach of the House of Commons' rules on conflicts of interest.

[9] Marples Ridgway was also involved in other major road projects in the 1950s and 1960s [17] including the £4.1 million extension of the M1 into London, referred to as the Hendon Urban Motorway at the time.

[19] In early 2020, the rumours were corroborated by broadcaster and investigative journalist Tom Mangold, based on the diaries of Lord Denning's then-secretary, Thomas Critchley.

[22] Among the journalists who investigated his unexpected flight was Richard Stott (later editor of the Daily Mirror): In the early 70s ... he tried to fight off a revaluation of his assets which would undoubtedly cost him dear ...

He left by the night ferry with his belongings crammed into tea chests, leaving the floors of his home in Belgravia littered with discarded clothes and possessions ...

Tenants of his block of flats in Harwood Court, Upper Richmond Road, Putney, London, were demanding that he repair serious structural faults and had threatened legal action.

[22] In addition, in 1974, he had lost 130 cases of wine to a fire in a store he owned under a railway line in Brixton,[24] and he had been convicted of drinking and driving for which he received a one-year ban and a £45 fine.

[26] In November 1977, he paid £7,600 to the British government in settlement of his breach of exchange control regulations, following which he made a return to London where, with agreement from HMRC, he was allowed to stay with friends for six weeks.

[26] By now Marples had sold Chateau Chaintre and his final years were spent on his 18-hectare (44-acre) vineyard estate in Les Laverts, Fleurie, France.

[29] In 2009, his name was used for a website, ernestmarples.com, that campaigned to have the UK Postcode dataset released as Open Data and drew threats of legal action by the Royal Mail against its founders.