Ministers reply.
In a debate on the main floor of the House you will get ministerial statements from the front benches. You have the government and the opposition at the start, and then with these three-hour debates around petitions, the front benches wind up at the end, normally with about 10 to 15 minutes for each side.
Really, these debates are very much an opportunity for backbenchers to express themselves and for the government to listen and respond in a concise way.