What process did we go through to rank the supermarkets? A description of PAN UK’s methodology

Below is a description of the process that PAN UK went through to produce our supermarket ranking. It was an extremely detailed process, so we have just given an overview, but are happy to answer additional questions so please do contact us if you want further information.

Stage 1: Supermarkets selected

PAN UK’s 2024 survey builds on work conducted for our 2019 and 2021 ranking. For both 2019 and 2021, we selected supermarkets based on their share of the UK groceries market. This gave us a list of the top ten supermarkets in order of grocery market share: Tesco, Sainsbury’s, Asda, Morrisons, Aldi, Co-op, Lidl, Waitrose, Iceland, M&S.

The list of top ten UK supermarkets remains almost identical in 2024, except that Spar has replaced M&S at number ten. Despite this, we chose to keep the same selection of supermarkets for the 2024 ranking since it enables us to assess how much progress they have made over the past five years. While we very much hope to keep working with M&S, we will consider changing the list of supermarkets that we include for the next ranking in 2026 in an effort to cover as much of the UK groceries market as possible.

Stage 2: Survey sent to supermarkets

We sent a survey to each of the ten supermarkets, with an eight-week deadline to respond. The survey asked detailed questions about six topics related to pesticides in supermarkets’ global supply chains. While the key focus was on actions the supermarkets are currently taking, we also took account of any progress made since the 2021 survey and ranking. The six topics included in the survey were as follows:

Download the full PAN UK supermarkets survey here.

Two weeks after the survey had been sent out, we held an online webinar for supermarkets to help them understand the survey questions and marking criteria.

Stage 3: Supermarkets scored and ranked

After eight weeks, PAN UK received survey responses from all of the top ten supermarkets. We set about analysing and scoring the responses. Whenever possible, supermarket survey responses were cross-checked against publicly available information.

The majority of the survey questions were qualitative, but some were quantitative. Each answer was scored from low to high. A higher score was received when a supermarket was doing well compared to other supermarkets, and likewise a low score was received if a supermarket was doing comparatively badly.

Based on their scores, supermarkets were allocated a ranking for each of the six topics of ‘lagging behind’ (1 trolley), ‘could do better’ (2 trolleys), ‘making good progress’ (3 trolleys) or ‘leading the way’ (4 trolleys). These scores were then weighted based on how much of an impact that action in that particular area would have on reducing pesticide-related harms. So, for example, supermarkets scored more points for efforts to phase out Highly Hazardous Pesticides than for becoming more transparent.

Once weighted, each supermarket’s total number of trolleys was added up and then divided by the total number of relevant topics to reveal the final ranking positions. Most supermarkets’ scores were therefore divided by six because all six topics are relevant for their supply chains. However, two supermarkets (M&S and Iceland) do not have gardening or pet ranges and therefore don’t stock pesticide products, and so their scores were calculated as an average of how they performed over five topics. PAN UK staff have been working closely with supermarkets for many years now, so when two supermarkets received the exact same total number of trolleys, we either allocated them the same joint position in the ranking or used our detailed knowledge of their policies to decide their final positions in the overall ranking.

For each of the six topics, supermarkets were marked against four main criteria:

What is PAN UK’s ideal vision?
What is realistically possible in terms of where the supermarket sector is currently?
How do the actions taken by each supermarket compare to those taken by other supermarkets?
What’s the sector doing as a whole?

While many supermarkets mentioned measures designed to ensure that they do not break pesticides laws in the countries where they operate, we did not give points for these actions. PAN UK expects all supermarkets to follow national pesticides law and, as such, points were only given for measures that go beyond legal compliance.

It is worth noting that as the UK supermarket sector as a whole makes progress on pesticide reduction, the measures needed to achieve a score might evolve. So, for example, in the 2021 ranking, a supermarket that published its pesticide policy might have received a high score for transparency since they were one of the few to do so. However, the sector has made progress in transparency over the past three years, so the same supermarket might find itself with a lower transparency score in 2024 if they have made no further progress. Similarly, a supermarket may come lower in the ranking than they did previously, not because their own efforts have reduced, but because other supermarkets made more progress and so overtook them.

Stage 4: Supermarkets given an Opportunity to Comment

Following our analysis, we sent each supermarket an outline of what we were planning to publish about them and gave them 18 days to respond. We received responses from all supermarkets except for Lidl and Iceland. PAN UK has represented the responses we received as fairly and honestly as possible, while making them comprehensible and engaging to the public.

Next steps

In 2025, PAN UK plans to continue to work closely with as many supermarkets as possible to support them to implement our recommendations. In 2026, we will send another survey to UK supermarkets and they will once again be scored and ranked according to a similar methodology. Through our ongoing efforts, we hope to continue assisting UK supermarkets to make considerable headway in reducing pesticide-related harms linked to their global supply chains.