Liz Truss’s new chief economic adviser wanted to scrap HS2 and the Equality and Human Rights Commission as part of a plan to cut £7 billion from public spending.
Matthew Sinclair said supporters of the high speed rail line “haven’t convinced free market economists” it was value for money.
And he said the ECHR had “taken on a campaigning role that is inappropriate for a public sector body”.
He made his comments in an article for the ConservativeHome website in 2012, when he was director of the Taxpayers’ Alliance.
Elliott claimed that getting rid of the ECHR would save £48.9 million at that time.
Explaining the move, he said: “There are two key reasons why we called for the EHRC to be abolished: it has taken on a campaigning role that is inappropriate for a public sector body; and it has shown it cannot be trusted with taxpayers’ money.”
Elliott added: “The Equality and Human Rights Commission does have a regulatory role but, where there is serious discrimination, that should be a matter for the courts.
“There is no fundamental need for the quango. Even if legislation does need to change in order for it to be abolished, that would be worth it.”
On HS2, Elliott said: “Proponents of a new line just haven’t convinced free market economists and commentators, people who do appreciate the case for infrastructure investment, that this is the right project.
“Besides simple train envy, the principle case for the line seems to be that the business community wants it, or the Midlands and the North want it.
“But when you actually survey people you find that business leaders are unconvinced by the case for the scheme, and the Midlands and Wales – the only place that will see a new connection to London this side of 2030 – is one of the areas where people are most in favour of cutting the project. In terms of public opinion this isn’t a North versus South issue.”
Elsewhere in the article, Sinclair called for a reduction in the number of Whitehall departments and the scrapping of the government’s Green Investment Bank.
It has previously emerged that Sinclair - who was a director and economics adviser at Deloitte before taking up his Number 10 role - wrote a book in 2011 attacking green taxes.
A Labour source: “It’s clear that Liz Truss’ economic policy is going to be the same, failed Tory ideas that got us in this mess - but this time on steroids.”
A Lib Dem spokesperson: “This appointment reveals the contempt with which Liz Truss and the Conservatives hold the British people.
“The causes Sinclair has championed, undermining our human rights and slashing investment in the economy, are the last thing our country needs at this time of crisis.
“Liz Truss should focus on tackling soaring energy bills and NHS waiting times rather than appointing yet another right-wing ideologue.”
Downing Street has been approached for comment.