A few weeks back the Observer published an article by Jason Langrish, a member of the Canadian team that negotiated the recent CETA trade deal between the EU and Canada. He was unsparing about the utter mess of the government's approach to Brexit and the catastrophe that it risks. The line I found most telling, not least because I think it also partly identifies the hole in which Labour finds itself, is that the government is still in "campaign mode". Ministers are still only giving us, and indeed Brussels, a very general sense of what they intend to do.

Last month some of my colleagues also published a report on social integration that, among other things, advocated the further exploration of a system of regional immigration controls. A few days later, Jeremy Corbyn seemed in quick succession both to accept and to reject further controls on immigration.

To me, a large part of Labour’s problem comes from a public debate over Brexit that confuses at least three very different issues and very different contexts for any debate on immigration. The first issue is: "What would our immigration policy look like if we started from scratch?"

The second is: "How much free movement within Europe should we be prepared to accept as part of a Brexit deal" – that is, "how hard do we want our Brexit?". Sadly, this is a question on which we may get very little say as a party, though that does not mean it cannot do us plenty of damage in the interim.

The third and realistically only question with which a Labour government might have to contend is: "After Brexit, what should our immigration policy look like given public sentiment and the nature of our economy?". It is plain to me that this is where our attention should be focused, and that we should be realistic about how we might get there and what that might look like. It is also plain that we're not really there yet.

On the first issue of what our immigration policy would look like if we started from scratch, opinion polling suggests that a majority of people in Britain would probably agree that skilled migrants who plug identified gaps in our economy, who have family members here already, and who speak English and are keen to get involved in civic life should be allowed in – and should be welcomed. A majority would also probably agree that unskilled migrants who don't speak English and have neither a job nor family here, nor a reasonable expectation of getting a job very soon, should not be allowed in. The devil is very much in the detail. As someone who consistently argued that Britain is better off within the European Union, it is worth reiterating that many of us who believe that the free movement of people within the European Union has been good for Britain and helped our economy do not believe that uncontrolled immigration is a good thing in itself. Were we a new country we would also not have ties to countries all over the world, much further away geographically even if often very close culturally, that come from Britain's imperial past.

The second issue of how much free movement within Europe we should accept as part of a Brexit deal is one where ultimately Labour has limited capacity to make a difference. It is very clear to me that a majority of people in my constituency and across the country voted to leave the European Union. It is also very clear that attitudes towards immigration were central to this.

My view is that the best deal for Britain is one that keeps as many as possible of (in no particular order): single market membership; customs union membership; European Court of Justice jurisdiction over trade disputes and similar between the United Kingdom and its European partners; continued passporting rights for our financial services industries; technical co-operation on matters of joint interest such as nuclear power and nuclear safety; and the maximum possible freedom of movement rights for British and EU citizens alike.

I am intensely aware that the ability of the Opposition to achieve any of this is not huge, especially given the likelihood that many SNP MPs may take the view that their party interest is better served by a bad deal for their constituents so that separatism becomes a more appealing prospect. This is yet another reason why we should be furious with ourselves for failing to win in 2015, and why we should focus so ruthlessly not just on holding our own seats but also on those of our opponents.

I also believe we should not hesitate to continue to stand up for what we believe is in the best interests of working people in our country, rather than what we think a narrow majority of the British people want to hear right now. We must be an alternative political leadership, not advocates for positions in which we don’t actually believe.

The British public can easily see through politicians who don't themselves believe in what they are saying and who only say what they think voters want to hear. They don't trust them. One of the many lessons from Donald Trump’s victory is that politicians who appear sincere in their belief in transparently catastrophic policies can be more successful than those who display admirable self-doubt. It is an unhappy message for those among us of a cautious disposition who value reason and evidence, but a powerful one nonetheless. I believe that in the medium and long term, the public will reward people who stick to their beliefs.

The third issue on the question of what our immigration policy should be post-Brexit is the one where I think that Labour has to start doing better. I admire the work of colleagues on the APPG on Social Integration, but I hope they will forgive me for saying that my admiration for their efforts is not matched by agreement with their recommendations. I was, for example, genuinely taken aback by their suggestion that the UK could learn from the Canada-Quebec accord on immigration.

There are two obvious reasons why any form of regional control of immigration wouldn't work in Britain. The first is that this is a much smaller country, and therefore travel between major population centres is extremely easy. How, for example, would people who had residency status in Scotland be prevented from turning up in Sunderland? Are we to rebuild Hadrian's Wall? Will motorway speed cameras be joined by watchtowers?

The second is if anything even more obvious: Quebec is a French-speaking province of an otherwise largely English-speaking country. People are less likely to move to a different province if they cannot get by in the language spoken there. While we have probably all struggled on occasion with the accents of people born and brought up elsewhere in Britain, almost everyone who has grown up on this island speaks English. Our governmental structures are also markedly different to those of Canada.

The reality too is that our economy is dependent on immigration, and the contribution of migrants has driven our country’s economic success. Our social model, above all the NHS, rests heavily on immigration, but I want to focus here on the economic issues.

One of our export success stories, and one that also gives us tremendous soft power, is higher education – that is until the government started to throttle it. Higher education only works as an export industry if you let people in before asking them to go home. Yet today we see a crackdown on student visas wholly disproportionate to the level of their abuse, and a general failure to understand how crucial higher education is to our economy. You only have to walk around Sunderland to appreciate the impact that international students have made upon the city, and the investment and wider benefits that an expanded university has brought for the entire community.

Another important part of the UK economy is agriculture. For a variety of historical reasons, the United Kingdom has a relatively small agricultural workforce and a high degree of agricultural mechanisation. But that means that for some jobs that have not yet been automated, we have labour requirements that are unusually seasonal. There are not yet mass-market droids for judging the ripeness of a strawberry and then picking it without crushing it. The strawberry-picking season is short, so the sector has seasonal acute labour force requirements for people with fairly easily acquired skills rather than a persistent shortage of people with highly specialist skills.

What's also true is that for these people, who may only pick fruit for a few short summers and spend the rest of their lives overseas, the challenge is much more about preventing their exploitation than it is about ensuring their integration. I am unconvinced that everyone who works picking apples or strawberries on a summer job here needs to know English before they arrive. It's obviously great if they do, and they may well learn the language whilst working, but a degree of realism might usefully intrude into our discussions.

Perhaps the most obvious British economic export is financial services. London is the financial capital of Europe, although that may not continue for much longer. People working in financial services come from all over Europe, and the taxes they and their companies pay in London provide much of the money for the services on which we all depend.

I believe very strongly that we have a desperately unbalanced economy. Geographically we are too focused on London and Edinburgh and sectorally we are too concentrated on finance - but the first step to reduce our dependence on a goose that lays golden eggs cannot be to stab the goose. In the short and medium term, that means we have to make sure that the financial services sector does not suffer disproportionately. London may be the financial capital, but jobs in the sector are spread across every part of our country.

Even after Brexit, we will need to keep financial services - institutions, jobs, and regulatory expertise - in Britain. That will mean being open to people from across Europe working in that sector and ensuring our country remains a global centre for financial services.

Lastly there is the key industry in my own city: car manufacturing, which depends both on access to big markets in which to sell the products and a highly skilled workforce to build them. We don't know exactly what Theresa May has said to Nissan, beyond that they have now made the very welcome announcements about future work at the Sunderland plant, but my fears are threefold. First, I am concerned that the company may have been promised inducements which will not be available to new entrants to the British manufacturing sector, making us more rather than less dependent on current goodwill. My second fear is that restrictions on Nissan's ability to move top-flight engineers here from elsewhere in Europe, even if just in paperwork, may make Sunderland a less attractive destination for future research and development. And my third worry is that a patchwork of deals and site-specific support is so far from being an industrial strategy as to be laughable. It isn't even "picking winners": it's picking companies we'd rather weren't losers.

All of these concerns make me highly receptive to a policy position and a political strategy based on the industries we already have, which of these a Labour government would want to flourish post-Brexit, to what extent they depend upon immigration, and how their labour force requirements are structured across both skills and seasons. Our focus as a party should be on how we reconcile the clearly expressed view of the public for national immigration controls with building an open and successful economy that provides high quality jobs for the people we represent. We need to listen, but we also need to be more candid about the complexity of the challenge we face.