Warm the oil in a large non-stick frying pan with the chilli flakes, garlic and olives for 1-2 minutes. Add the capers and tomato purée, pour in the wine and bring up to a simmer, then stir in the chopped tomatoes and simmer for 15 minutes to thicken.
Meanwhile, bring a large pan of salted water to the boil and cook the pasta until al dente according to the packet instructions. Drain loosely, saving a cupful of the cooking water.
Once the sauce has thickened, stir in the mackerel and heat for a couple of minutes to warm through, then stir in the pasta with a splash of the cooking water and toss well to mix. Sprinkle with the parsley and serve with lemon wedges for squeezing.