OK thanks.
That`s what I thought but then I saw this.
Important: You are not entitled to receive the Canada Emergency Response Benefit (CERB) from the Canada Revenue Agency (CRA) while you are receiving Employment Insurance (EI) benefits or the CERB from Service Canada. If you have already submitted an application with Service Canada for EI or the CERB, you cannot apply for this benefit through CRA.
For my subsequent CERB applications: I continue to not work and expect to remain in this position for the entire four week period for which I am applying and expect to receive no more than $1,000 in combined employment or self-employment income.