Demonstrators sat in the road to block traffic, chanted and waved anti-racist placards ahead of the far-right activist’s arrival in Bootle on Sunday afternoon.
More than 50 police officers separated the group from Robinson’s supporters, who shouted: “Tommy’s going to be your MEP.”
Scuffles broke out as a van, used by Robinson’s European Parliament elections campaign team, arrived in Douglas Place.
Eggs hit the windscreen of the van and a bottle containing a milk liquid was hurled from the crowd.
Robinson, who is standing as an independent candidate for North West England in Thursday’s vote, was escorted by police through a back alley.
He was greeted by cheers from his own supporters while counter-protesters booed and shouted “fascist scum”.
Robinson, real name Stephen Yaxley-Lennon, spoke at the rally for around an hour before being escorted away by police.
Bootle MP Peter Dowd, who joined the counter-demonstrators, said Merseyside Police should have called off the visit.
He wrote on Twitter: “Stephen Yaxley-Lennon aka fascist Tommy Robinson isn’t wanted in Bootle. Don’t bother coming here.”
Anti-far-right activists have regularly adopted the tactic of throwing milkshakes as a form of protest at candidates – possibly because milk has previously been used as a symbol of the far-right and white supremacy.
Robinson was hit with milkshakes twice in two days in Bury and Warrington earlier this month.
And on Sunday afternoon UKIP MEP candidate Carl Benjamin had a milkshake thrown over him while campaigning in Salisbury – the fourth time in a week.
Additional reporting by PA