P_{1.4 GHz}−M₅₀₀ correlation plot of radio haloes. To account for the discrepancies between the ACT and Planck mass derivations, we use the uncorrected M_500c values for the ACT clusters (Hilton et al. 2021). The solid line shows the best-fit relation, with parameters extracted from the low-redshift sample (z ∼ 0.2) presented in Cassano et al. (2013), this fit was performed using linear regression in the log-log space by adopting the BCES-bisector method. The Di Gennaro et al. (2021a) sample consists of radio haloes at z > 0.6, and the Knowles et al. (2021) sample covers 0.22 < z < 0.65. We also include El Gordo, which is at z = 0.87 (Lindner et al. 2014).