"That means businesses need to have confidence that there will not be a cliff-edge when we leave the European Union in just over twenty months' time", the pair write.
Prime Minister Theresa May formally triggered the Brexit process on March 29 and divorce negotiations officially began on June 19.
Chancellor Philip Hammond and International Trade Secretary Liam Fox have attempted to quell any accusations of a divide within the government over the UK's approach to Brexit.
"Over the summer, we heard that Philip Hammond was courageously fighting off the more extreme Brexiteers".
They also underlined that Britain would operate outside the single market and customs union after Brexit. He has now teamed up with one of the more extreme and ideological supporters of a "hard Brexit".
Foreign Minister Boris Johnson said in a tweet that the article was the "right way forward" and would "create certainty and a great new European relationship". "Get job done + on with Global Britain", he wrote on Twitter.
Hammond and Fox wrote in the article, that a time-limited interim period must be established to ensure proper Brexit.
"But we are also clear that during this period our borders must continue to operate smoothly; goods bought on the internet must still cross borders; businesses must still be able to supply their customers across the European Union and our innovative, world-leading companies must be able to hire the talent they need, including from within the EU".
The UK will leave the Customs Union and Single Market they said, writing in the Sunday Telegraph, but there will be a "time-limited" transition period with the aim of helping business adjust and to avoid a "cliff-edge".
Meanwhile, the leading Conservative Remainer Anna Soubry indicated she could be prepared to join with politicians from other parties to stop the country "staggering recklessly" towards a hard break with Brussels.
"Could I ever see myself joining with like-minded people who want to save our country from such an appalling fate?"
"But I would be betraying my principles if I did not make it clear that country must always come before party". The EU's chief negotiator, Michel Barnier, warned EU ambassadors last month that the lack of progress meant talks on the future relationship with the United Kingdom, including a free-trade agreement, may not be possible by the next leader's summit in October, and may have to extended.
"We will leave the customs union and be free to negotiate the best trade deals around the world as an independent, open, trading nation", the article said.
"The referendum will be no excuse if the country is driven off a cliff", he declared.
Mr Miliband, who narrowly lost out to his brother Ed in the 2010 Labour leadership contest and who now heads the International Rescue Committee relief agency in NY, described the outcome of the 2016 referendum as an "unparalleled act of economic self-harm".