The bill is intended to tackle a wide range of harmful online content, such as cyber-bullying, pornography and material promoting self-harm.
Social networks could be fined or blocked if they fail to remove harmful content, and their bosses could be imprisoned for a lack of compliance.
Labour said the bill’s delays meant disinformation in the UK was growing.
The bill’s regulator Ofcom will have the power to request information from companies, and executives who do not comply could face up to two years in prison within two months of the bill becoming law.
Senior managers would also be criminally liable if they destroyed evidence, did not attend an Ofcom interview, provided false information, or otherwise obstructed the regulator from entering offices.
Any firm breaching the rules would face a fine of up to 10% of its turnover, while non-compliant websites could be blocked entirely.
Culture Secretary Nadine Dorries said the bill meant tech firms weren’t left to “check their own homework”.
“Tech firms haven’t been held to account when harm, abuse and criminal behaviour have run riot on their platform,” she said.