Chris Grayling is Leader of the House of Commons, and MP for Epsom and Ewell.

The old days are here again.  Derek Hatton and George Galloway are talking about rejoining Labour.  The militants are back.  The hair might be greyer – but their views are the same as ever.

As Conservatives, we are all watching the Labour leadership contest unfold with a mixture of amusement and amazement. But regardless of the end result, it’s pretty clear that the political arguments we won in the 1980s are now back in play again. That’s something that we as Conservatives should be very aware of, and be prepared for.

Union militancy is clearly back on the agenda. It’s not just about the strikes on the tubes and the trains this summer – however unjustifiable they are. Union leaders are flexing their muscles and threatening industrial action more. That’s why Sajid Javid’s new rules that require a proper level of support before a strike can be called will be so important.

Nationalisation is also back on the agenda. You’d expect that from Jeremy Corbyn. But now that Andy Burnham is also committed to renationalising the railways, the direction in which Labour and the union movement is heading is very clear.

Quite why anyone would want to return to the days of British Rail is beyond me. Politicians may argue over the structure of the railways, and the performance of Network Rail. But the union view on rail privatisation is a million miles from the truth. Passenger numbers which had been in decline for decades have doubled. New routes and new stations have been opened. New trains are running across the network. Our challenge now is creating the capacity to meet demand. Does anyone really think that this would have happened if British Rail had survived?

Wealth taxes are also back on the agenda of the left. Gordon Brown pushed the top rate back to 50 per cent. It didn’t work. It raised less money from top band taxpayers, not more. We cut that rate. Now the left want to raise it again – some to even more than 50 per cent – even though that change would drive wealth and wealth creation out of the country.

Even unilateral nuclear disarmament is making a comeback, with more and more on the left now saying that we should not replace Trident – even though it was Margaret Thatcher and Ronald Reagan’s determination to maintain the most up to date deterrent that won the Cold War.

But perhaps the biggest battle to fight is over so-called “austerity”. Its opponents present this as an ideological choice rather than what it really is – a country sensibly choosing to live within its means. Across Europe parties have emerged from their bunkers to rail against “austerity”.

What they really want is for nations to carry on spending money on the never-never and hope it will be alright in the end. But as the Greeks found out, in the end people won’t lend to you, and you have to be bailed out by other countries.

Under Conservative leadership, Britain has rejected that path, and made real progress in putting our nation’s finances in order. It would be the height of irresponsibility to simply abandon that work, and borrow, borrow, borrow.

There’s an old saying that “what goes around comes around”. It’s clear that the ideological battles of the 1970s and 1980s are making a comeback. Arguably the Conservative Party’s finest post-war hour was Margaret Thatcher’s defeat of an ideology that was bleeding Britain dry.

Whatever happens in Labour’s leadership contest, it’s clear that there are those that want to have those same old arguments, all over again.  We will have to make sure that their arguments are no more successful than last time.