Fill a large pot with lightly salted water and bring to a rolling boil over high heat. Once the water is boiling, stir in the linguine and return to a boil. Cook the pasta uncovered, stirring occasionally, until the pasta has cooked through but is still firm to the bite, about 11 minutes. Drain well in a colander set in the sink.
Heat 1 tablespoon of olive oil in a frypan over medium heat. Stir in the garlic and onion; cook and stir until the onion has softened and turned translucent, about 5 minutes. Heat another tablespoon of olive oil in a large frypan over medium-low heat. Stir in diced tomatoes and spring onion; cook and stir until the tomatoes have softened. Stir onion mixture into the tomatoes, then add crushed tomatoes, tomato paste, oregano and thyme. Simmer for 5 minutes.
Stir in mussels and prawns, then pour in the wine and lemon juice. Cover and increase heat to high. Cook until prawns have turned pink and mussels have opened, discarding any that have not opened. Serve over pasta and garnish with lemon wedges.