Fewer than 20 of Labour’s 232 MPs voted for Jeremy Corbyn to be their party leader, so he was hardly expecting rave reviews from the Parliamentary Labour Party. But even some of the select band who did back him admit he has had a shambolic first week in the job.

“You can’t be straight-talking and not talk to anyone,” said one MP ally, referring to Mr Corbyn’s refusal to appear on programmes such as the BBC’s Andrew Marr Show. Another MP supporter said: “It has been disorganised chaos.” Although Mr Corbyn never expected to win when he squeaked on to the ballot paper in May, his team had every reason to be confident well before his victory was formally announced a week ago. So the absence of a proper first week plan is surprising.

His strategy was not just woeful, it was non-existent. The election of a new leader is one of the few times when the public might tune in to politics, so there is a brief window of opportunity to engage them. Mr Corbyn’s surprisingly low public profile helped the Conservatives in their campaign to brand him as a risk to the financial security of everyone in the country as well as the security of the nation itself. First impressions stick, as William Hague, Iain Duncan Smith and Ed Miliband discovered to their cost.

The best way for Mr Corbyn to counter the attack would have been to be on the airwaves immediately after his victory. He does not look like the bogey man the Tories portray, and could have reached out beyond the fan club which elected him.

I understand Mr Corbyn’s distrust of the media. He will never get a fair deal from the right-wing newspapers. But it is crazy to shun broadcasters and other papers, who are not the enemy. Occasionally, even the right-wing press will do business with a Labour Opposition when it does not like what a Conservative Government is doing. The refugee crisis is a good example.

In his first week, Mr Corbyn cut off his nose to spite his face. His friends argue that, by electing him, Labour members were rejecting the control freakery and spin of New Labour. “He wants to do things differently,” one said. After his leadership campaign enthused thousands of people, his allies argue, “the movement is now the message”. But they will find that the mainstream media is still the message and the messenger to the millions. You can win a leadership election on Twitter, but not a general election.

The way the Shadow Cabinet was appointed was amateurish. Now that Labour has a male leader and deputy (Tom Watson), Mr Corbyn needed to give a high profile to women who, to the party’s credit, make up 40 per cent of its MPs. Rather than announce his whole team, he disclosed that the most senior posts would be filled by men – Hilary Benn, John McDonnell and Andy Burnham. As a desperate afterthought, he made Angela Eagle shadow First Secretary of State and invented two new posts for women so that 16 of the 31 Shadow Cabinet are female. In trying to avoid New Labour’s tricks, he ended up aping them.

The most significant development of the week was the way that Shadow Cabinet members stood up to Mr Corbyn – openly challenging his views on Europe, welfare and Ireland and criticising him for not singing the national anthem at the Battle of Britain memorial service. I doubt this is what Mr Corbyn had in mind when he spoke about democratising his party.

If he thought his mandate from the 250,000 members and supporters who elected him would give him untrammelled power, he now knows otherwise. On Monday, he told Labour MPs he would not give David Cameron a “blank cheque” in his negotiations on a new EU deal and kept open the option of campaigning for an Out vote in the referendum. By yesterday (fri) his U-turn was complete, as he accepted that Labour would urge an In vote. “We have beaten him to pulp on Europe,” claimed one moderate MP.

The damaging headlines about him not singing the national anthem at the Battle of Britain memorial service could easily have been tempered by a faster media response. It turned out that Mr Corbyn usually sings the anthem – and will do so in future – but, incredibly, this took three days to emerge. The real question raised by this controversy is: does Mr Corbyn really want to be prime minister? If he doesn’t go through the motions of trying, that will only help his enemies within.

True, he didn’t have a backroom team in place this week and has now made some senior appointments. There is still time – just – to define himself on his own terms rather than leave a blank page for the Tories to fill in. The British public are more fair-minded than the right-wing newspapers. When Gordon Brown succeeded Tony Blair as prime minister in 2007, the Tories thrashed around as they tried to find which of their scattergun attacks worked. The public’s attitude was “let’s give him a chance, let’s see what he’s like.” It took a year for many people to make up their mind about Mr Brown.

Mr Corbyn may not even have that long. His Labour critics, who admitted a week ago that his huge mandate from the party would stop them mounting an early coup, have already revised that view after what they see as his disastrous first week.