British Home Secretary Amber Rudd urged on Monday that stricter laws be imposed on people who stream terrorist content online.
She demanded that repeat offenders could be sentenced to up to 15 years in prison.
Britain has seen five deadly attacks this year, including vehicle and knife rampages and a bombing at an Ariana Grande concert in Manchester.
Rudd told the governing Conservative Party conference in Manchester that seven other plots had been stopped.
She said tougher laws are needed because there's been "a shift toward crude attacks" with shorter timescales.
She stressed the need to tackle extremism over the internet and update counter-terrorism laws related to it.
According to Home Office, some 44,000 websites for ISIS terrorist propaganda have been set up in the past eight months.
"There is currently a gap in the law around material which is viewed or streamed from the internet without being permanently downloaded,” Rudd told Sky News.
"This is an increasingly common means by which material is accessed online for criminal purposes, and is a particularly prevalent means of viewing extremist material such as videos and web pages."
She also hoped that the stricter laws would also include those who spread information about members of the armed forces, police and intelligence agencies for terrorist purposes.
Addressing ideologies that are an inspiration for this year’s terrorist attacks are without a doubt one of the biggest obstacles they are facing, but they are not the only ones, Rudd added.