Can my employer affect whether my claim gets approved?

Your employer is not responsible for approving your claim; your employer's insurance company is.

If you have sustained a workplace injury, you should definitely inform your employer about it as soon as possible. It'll also be good to inform them of your decision to lodge a workers comp claim.

However, once you've lodged your claim with SIRA, the decision for approval lies with your employer's insurance company.

Insurance approval usually takes about 1-3 weeks.

Hence, your employer has no influence over the outcome of your workers comp claim.