The latest opinion polls have produced a result polls have had three different parties in the lead
Sorry about the mess but its's the best I can do, to copy the data over. It's clearer here.
Clearly there is a Brexit Party, Liberal Democrat bounce and a opinion polling not seen since the 1980's when the SDP formed the SDP–Liberal Alliance with the Liberal Party in June 1981, under the joint leadership of Roy Jenkins (SDP) and Liberal leader David Steel. ] During an era of public disillusionment with the two main parties – Labour and the Conservatives – and widescale unemployment, the Alliance achieved considerable success at parliamentary by-elections. At one point in late-1981, the party had an opinion poll rating of over 50%.
That of course didn't materialise , but the above table does show a remarkable change in voting intentions.
With an average of about 2000 people sampled, the figures for both Plaid Cymru and the SNP are misleading