GERB and DPS voters were demobilised in Sunday's presidential election, according to the polling agency Myara. Andrey Gyurov won nearly half a million votes and has extra room to grow ahead of a run-off. Progressive Bulgaria (PB) has a bigger reserve, the agency's data on who voted show.

Myara's first exit poll results, at 7pm on Sunday, put the ticket of Iliana Yotova and Kiril Valchev in front with 35.2%. Gyurov and Georgi Kandev were second with 32.2%.

Where it began: Myara exit poll: Yotova and Valchev lead with 35.2%, Gyurov and Kandev on 32.2%

Neither GERB nor DPS had its own candidate. About 120,000 GERB supporters voted, nearly half of them for Gyurov and one in five for Yotova. At the last vote, months ago, the figure was well over 400,000.

Perhaps 50,000 DPS supporters voted. Almost half backed Yotova, and the rest split between other candidates, with Gyurov standing out among them. Months ago the figure was over 200,000.

The comparison with April relies on what voters themselves say about how they voted then.

People who voted for We Continue the Change – Democratic Bulgaria (PP-DB) in April make up more than a fifth of the current vote, or over 300,000 people. The coalition won more than 400,000 votes in the spring. Myara says a clearly higher share of PP-DB voters turned out than of GERB and DPS voters. That gives Gyurov more room to manoeuvre in a run-off. His nearly half a million votes show potential to reach beyond the party lines of PP and DB.

About 500,000 people, less than a third of those who voted on Sunday, say they voted for PB on 19 April. Among likely voters, firm support for the party is close to 40%, and a run-off could add a few more points.

Vazrazhdane voters also turned out. People who backed the party in April make up a tenth of Sunday's vote, roughly what it won then. Kostadin Kostadinov got 190,000 votes. Nearly 50,000 of them came from voters who returned to Vazrazhdane. Myara says these voters apparently mostly backed PB in April.

The same holds, on a smaller scale, for supporters of Ivelin Mihaylov and most voters of the smaller candidates. Among voters for Radostin Vasilev, Ivan Hristanov and GERB, it is the other way round: many often chose the option "I do not support anyone". It turns up either among young people or among GERB and DPS supporters.

Young people make up over 20% of Gyurov's vote and under a tenth of Yotova's. Nearly a third of her votes come from pensioners. The vote for Yotova, and in part for Kostadinov, skews towards middle-aged and older voters.

Myara says differences by place of residence are starting to show the usual divide that in Bulgaria is traditionally, and often wrongly, called left and right. In Sofia Gyurov leads two to one, while in smaller places it is the reverse. University graduates traditionally weigh more in the vote for candidates like Gyurov, and people with secondary education in the vote for candidates like Yotova.

Gyurov's vote skews slightly more towards women, but it is not clear whether women identified with a female candidate. There are no surprises by ethnic group, and slightly more Turks, as expected, voted for Yotova.

Myara has experimental data on a run-off between Gyurov and Yotova. Half of those who voted for Kostadinov on Sunday do not appear willing to vote. Among the rest, the split is two to one for Yotova.