Italy started the process of selling new 50-year and 7-year bonds via a syndicate of banks on Wednesday, having flagged the new issues the previous day.
Once recovery starts to take hold and investors buy into risk-bearing instruments, nominal bond yields will inevitably move higher and "no amount" of ECB buying can completely undo that.
Snowball also said the domestic game was projecting losses in excess of 100 million pounds ($137.22 million) by the end of April due to the impact of the pandemic.
The number of new confirmed coronavirus cases in Germany rose the most since Jan. 9, while the number of people with COVID-19 in French intensive care units set a high for 2021.
The European Central Bank may need some time before the recently agreed acceleration in the pace of money printing, ECB President Christine Lagarde said on Thursday.
"In my view, this hybrid model could be a possible compromise way forward, as long as an EDIS with full risk-sharing, covering both liquidity needs and losses in the steady state, remains the end goal," de Guindos said in a speech.
Ten-year US Treasury yields rose to over 1.63%, their highest level since February 2020 and their German equivalents, the benchmark for the region, rose as high as -0.293%.
Italian 10-year yields, which outperformed the market on Thursday as the country is among the top beneficiaries of ECB bond buying, were up 5 basis points at 0.63%.
The sources said policymakers set on a monthly target for the its Pandemic Emergency Purchase Programme with a small tolerance band around it but agreed not to reveal it.
One of the sources said the ECB aimed to push down yields to where they were in December while another said improved economic prospects meant part of the recent increase in yields was justified.
The ECB bought 11.9 billion euros worth of bonds under its Pandemic Emergency Purchase Programme (PEPP) in the five days to March 5, slightly less than in the previous week.
An ECB spokesman said the net purchases were affected by "seasonality factors", particularly large redemptions, which "temporarily delayed" an increase in the ECB's bond pile.
Some policymakers argue that the steady increase in bond yields is an unwarranted increase while others argue that it is a reflection of what is likely to be a robust recovery in both growth and inflation after the pandemic.
Growth on the other hand could fall short of projections in the first quarter due to widespread pandemic-related restrictions, even if full-year activity is still seen in line with the bank's 3.9% projection made in December, de Guindos said in a webinar with investment bank Berenberg.
"These developments underline the importance of avoiding premature increases in nominal interest rates," de Cos added.
The ECB will next meet on March 11 and while an outright increase in the 1.85 trillion-euro Pandemic Emergency Bond Purchase quota is not likely, the ECB could say it will increase the flow of purchases to cap yields.
The large redemptions meant the ECB added just 13.7 billion euros worth of debt to its holdings in the five days to Feb. 26, less than some investors were expecting.
The ECB already examines the suitability of board candidates in a so-called fit and proper assessment, but rules across the 19 euro zone members vary, so the quality of these checks can be inconsistent.
Supervisors will consider furthermore all of the diversity-related aspects that are most relevant to enhancing the individual and collective leadership of boards.
Italy has been without a fully functioning government for almost a month since the centre-left coalition collapsed, forcing Giuseppe Conte to resign as prime minister.